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Discussion Starter #1
I am building a 467 stroker motor i have two sets of heads 670 rebuilt few 1000 miles ago and 061 also rebuilt few 1000 miles ago i would send the heads in for a check up not sure if 061 is big valve head did not remove from good running 400 to check any way i dont know enough about castings to pick best set i have my67 gto set up with ram air car and auto thm 400 .want to get best low end power for street driving cam is comp cam 274 piston dished 9.2 cr with 72 cc heads need all the info i can get thanks guys
 

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Both of those are big valved heads, both look like high perf heads, which mean screw in studs. If both are rebuild and have similar miles, I'd guess they will probably be pretty similar in regards to flow. The 670s look like they have smaller chambers by looking on the net HOWEVER I would take that with a huge grain of salt and find a burette/plate setup to CC them. I would also probably not assume that the "rated" comp is what your engine will be and calculate it out based on compression height/dish volume.
 

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The 670 heads have a closed chamber design and 72cc chamber. Rated by many as to be one of the best flowing intake passages -stock. But, being closed chamber, I'd skip them. You want to use the 061's. It too is listed as 72cc's. The 061's were the first of the open chamber heads AND the chamber is pretty darn close to the Ram Air II, IV, HO, & SD chambers. If you put them alongside any other open chamber heads, you will see that the other heads have a deeper set chamber. Should promote a better burn. Both heads have the 2.11/1.77 valves, but 067 heads have the screw in studs. The 061 has press in studs and the AIR holes in the port pockets. I have a set that I plan on using on my 462 engine if they pass the machine shop inspection. I want them because of the chamber configuration. I will add the screw in studs. There are a couple options to add these which I found on the internet, but your machinist should be able to work with you on this. I will also be doing my own port matching/polishing etc.. Get Jim Hand's Pontiac (Got mine on Amazon) if you think you might want to tackle this yourself as the book guides you through the process. In my build, I am looking at the forged pistons having a dish in them to lower that compression as well. I am also going with forged rods which is not that much more when you consider reconditioning the stock cast rods. Cast pistons and rods are fine if you can keep your RPM's to the factory redline and don't hammer it all the time. Me, I like to wail on my cars, so I go with a little more insurance. Cam choice is wide open and everyone has an opinion. The factory knew what they were doing and made great grinds. Each cam grinder seems to have his/her take on what is best, what RPM range, needed engine parts, gear rations to use, etc.. -very confusing to say the least. You want to match up your car weight, trans & rear gear ratio, tire size, and the RPM range you want your motor to spin. Now you can grind a cam for torque or HP, lower, mid, & upper ranges, so you again want to match it to your car specs and your driving requirements. I always build a Pontiac for torque, but know a lot of torque spins those tires easily, especially in wet road conditions. You can move the torque range up or down depending on your cam selection. Seems most grinds are on a 110 LSA centerline while the factory was nearer to 113 LSA. The 113 LSA gives a broader power range over all. So another consideration. So, you really have to put some thought into a cam. My selection is on a 112 LSA. Be careful on some of these blogs/forums because it seems just about everybody is a camshaft technologist and will quote flow number, theory, and computer dyno programs. Again, Jim Hand's book is very helpful here and gives comparative facts based on his 467 CI street/strip '71 Lemans wagon. This book also has 13 pages of Pontiac engine builders engine combinations with CI sizes, estimated 1/4 mile times, engine parts selection, cam specs, etc. that can be very useful to any Pontiac engine build. I have an assortment of Pontiac engine building books/guides going back into the '70's and Jim Hand's book is a contemporary printing with all the good info you need to know to produce a solid running performer.
 

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Your big problem with using either of those heads on a 467 is going to be compression ratio. You're going to need massive dishes in your pistons to even have a prayer of making the engine live on pump gas, AND you'll probably have to run thick head gaskets too (which will destroy any quench pad effect you have in the chambers). Unless you have some overriding reason that you absolutely positively must run one or the other, then my vote is "neither". If you want to run cast iron D port heads, you'd be much better off finding a good set of 6x-4's.

Bear
 

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Discussion Starter #5
The 670 heads have a closed chamber design and 72cc chamber. Rated by many as to be one of the best flowing intake passages -stock. But, being closed chamber, I'd skip them. You want to use the 061's. It too is listed as 72cc's. The 061's were the first of the open chamber heads AND the chamber is pretty darn close to the Ram Air II, IV, HO, & SD chambers. If you put them alongside any other open chamber heads, you will see that the other heads have a deeper set chamber. Should promote a better burn. Both heads have the 2.11/1.77 valves, but 067 heads have the screw in studs. The 061 has press in studs and the AIR holes in the port pockets. I have a set that I plan on using on my 462 engine if they pass the machine shop inspection. I want them because of the chamber configuration. I will add the screw in studs. There are a couple options to add these which I found on the internet, but your machinist should be able to work with you on this. I will also be doing my own port matching/polishing etc.. Get Jim Hand's Pontiac (Got mine on Amazon) if you think you might want to tackle this yourself as the book guides you through the process. In my build, I am looking at the forged pistons having a dish in them to lower that compression as well. I am also going with forged rods which is not that much more when you consider reconditioning the stock cast rods. Cast pistons and rods are fine if you can keep your RPM's to the factory redline and don't hammer it all the time. Me, I like to wail on my cars, so I go with a little more insurance. Cam choice is wide open and everyone has an opinion. The factory knew what they were doing and made great grinds. Each cam grinder seems to have his/her take on what is best, what RPM range, needed engine parts, gear rations to use, etc.. -very confusing to say the least. You want to match up your car weight, trans & rear gear ratio, tire size, and the RPM range you want your motor to spin. Now you can grind a cam for torque or HP, lower, mid, & upper ranges, so you again want to match it to your car specs and your driving requirements. I always build a Pontiac for torque, but know a lot of torque spins those tires easily, especially in wet road conditions. You can move the torque range up or down depending on your cam selection. Seems most grinds are on a 110 LSA centerline while the factory was nearer to 113 LSA. The 113 LSA gives a broader power range over all. So another consideration. So, you really have to put some thought into a cam. My selection is on a 112 LSA. Be careful on some of these blogs/forums because it seems just about everybody is a camshaft technologist and will quote flow number, theory, and computer dyno programs. Again, Jim Hand's book is very helpful here and gives comparative facts based on his 467 CI street/strip '71 Lemans wagon. This book also has 13 pages of Pontiac engine builders engine combinations with CI sizes, estimated 1/4 mile times, engine parts selection, cam specs, etc. that can be very useful to any Pontiac engine build. I have an assortment of Pontiac engine building books/guides going back into the '70's and Jim Hand's book is a contemporary printing with all the good info you need to know to produce a solid running performer.
pontiacjim the 061 heads are screw in studs may have put in on last rebuild my cam is compcam xe274h-10 i also have jim hand pontiac max performance book i even got 2nd one when it came out more updated books are awesome but its hard to find info a the 061 head my pistons are costom from buttler deep dish made for 72 cc heads lot of info on the 670 but not 061 i dont think pontiac used 061 on GTO i am running the ram air set up so i was looking to make killer street car dont care about top end just want melt the tires and the street on a track of corse :rolleyes:
 

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Discussion Starter #6
Your big problem with using either of those heads on a 467 is going to be compression ratio. You're going to need massive dishes in your pistons to even have a prayer of making the engine live on pump gas, AND you'll probably have to run thick head gaskets too (which will destroy any quench pad effect you have in the chambers). Unless you have some overriding reason that you absolutely positively must run one or the other, then my vote is "neither". If you want to run cast iron D port heads, you'd be much better off finding a good set of 6x-4's.

Bear
Bear i got my stroker kit from buttler custom roos/buttler dish piston but buttler says to run factory head gaskets he says it will run about 9.2 cr with what i have with a 72.cc head
 

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Discussion Starter #8
How much dish is in the pistons? How many cc's, and what shape are they?

Bear
I was told the CR would be 9.2-9.5 1 with 72 cc heads but I never cc pistons ill take a picture and post it was a custom ross cut piston for 60.over 400
 

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pontiacjim the 061 heads are screw in studs may have put in on last rebuild my cam is compcam xe274h-10 i also have jim hand pontiac max performance book i even got 2nd one when it came out more updated books are awesome but its hard to find info a the 061 head my pistons are costom from buttler deep dish made for 72 cc heads lot of info on the 670 but not 061 i dont think pontiac used 061 on GTO i am running the ram air set up so i was looking to make killer street car dont care about top end just want melt the tires and the street on a track of corse :rolleyes:
My info comes from the book Pontiac Musclecar Performance 1955-1979 by Pete McCarthy and John Angeles. The 061 head came on the 400 CI full size cars with Carter 4Bbl carbs and was late production. However, my 061 heads are early according to the date stamping and as I recall had the Q-jet (but this could have been easily swapped. I did take them off a 1967 Catalina 4 Dr about 15 years or so ago. The dished pistons I believe, or as I recall, are about 30cc's which will give you the compression you desire. I already looked into this myself and it will be what I will use should the heads turn out o be usable for the rebuild. If not, I have a set of 7K3's which I already rebuilt that are on my 400CI and I have the original 1972 455 7M5's. I will order pistons to match whatever head I use. The 6X's seem to be a popular choice as you probably also read in Hand's book. I suppose being more plentiful is a key point. Personally, I think it is like asking what is the best carb size, manufacturer, single, 3 x 2, dual quads, fuel injection, etc.. Everybody has a preference and opinion. With heads, I think if you do just some basic port matching using the gaskets as templates, use 2.11/1.77 (or even 1.66 with the correct cam to compensate), screw in studs, SS valves, and good springs, you will have a good head for the street. Do a ton of work to the heads and you don't have the correct cam, intake, carb, good ignition, exhaust, gearing, etc., then in my opinion you won't notice much out of the heads. You want to keep intake velocity up based on RPM redline and cubic inches. Go too big on the heads when all else is not matched, you have a flat motor -better to go smaller. ON the other hand, you could have stock heads, tweak some/all the previous things and improve performance better than doing just the heads alone and not looking at the other components. I used to "tweak" the Pontiacs I owned as I never had money to do much else. I would rebuild/modify/fine tune the Q-jet, install an open element air cleaner or turn the lid upside down if I could not afford it, adjust the timing where it would "ping" (spark knock) under full acceleration and then back off a few degree until it didn't, add a 40,000 volt coil and good wires, (set the dwell correctly on the points), and if it had an automatic, install a shift improver kit from Napa. This usually made a big difference as throttle response improved and of course the quicker and harder shifting automatic added some (GTO TH-400's were modified like this from the factory -if it had not been changed out). Now my brother rebuilt his '67 GTO 400 with a Ram Air IV cam, 3 x 2's, had 4 speed/3.55's and added traction bars. The car had ton's of traction and power and he stress cracked the frame (now you buy braces to prevent this). He pulled out the Ram Air IV cam as he said it was too much for a street car and put in a milder cam -and the car still ran like crazy, but was more streetable. Just my 2-cents worth.
 

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I was told the CR would be 9.2-9.5 1 with 72 cc heads but I never cc pistons ill take a picture and post it was a custom ross cut piston for 60.over 400
Ok, so that's a bore size of 4.180, compressed head gasket thickness of .045, 72 cc's in the heads. Has the block been zero decked? If we assume 'not' and if we further assume the pistons wind up with the Pontiac 'usual' of .020 down, getting to 9.2:1 compression is going to require 30 cc's of dish in those pistons.

I highly recommend that you measure every last detail of every last part yourself and make absolutely sure you know what you've got there. Detonation and the results thereof are supremely ugly (and expensive).

Bear
 

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Discussion Starter #14 (Edited)
You do have what looks to be some pretty good dishes in those pistons. Did Butler give you any specs on them? Like how many cc's the dishes are?

Bear
yes looks like net dome cc's -30.000 ////// dish depht 0.246 ////// int v.p depth0.285 ///// exh v.p depth 0.285
 

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Discussion Starter #15
I did a cheap cc test on 670 and 061 heads looks very close 061 came out about 80 cc's 670 about 75 cc's think it would be less. cc's heads with spark plug in head ..Thank you guys for helping me out
 

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The 061's will do much better with today's fuel due to the chamber shape. The 670's closed chamber requires a ton of spark advance to make power...not ideal these days. If it were me, I'd run the 061's over the 670's hands down. I've used 061's on a 400 way back when, and they worked very well.
 

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yes looks like net dome cc's -30.000 ////// dish depht 0.246 ////// int v.p depth0.285 ///// exh v.p depth 0.285
Awesome. With 30 cc's in the pistons, 72 cc's in the chambers, +0.060 400, 4.250 stroke, you'll be sitting at 9.214:1 if the block wasn't zero-decked and pistons are the "usual" Pontiac .020 down.

I didn't know D-shaped dishes with that much volume in them were available. Nice :cheers

That being the case, definitely run the 061's. The open chamber is more efficient.

Bear
 

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Discussion Starter #18
Awesome. With 30 cc's in the pistons, 72 cc's in the chambers, +0.060 400, 4.250 stroke, you'll be sitting at 9.214:1 if the block wasn't zero-decked and pistons are the "usual" Pontiac .020 down.

I didn't know D-shaped dishes with that much volume in them were available. Nice :cheers

That being the case, definitely run the 061's. The open chamber is more efficient.

Bear
Thanks for your help 061 it is ..i have the roller tip comp cams rocker arms came on 061 heads i was going to re use would it be a waste to go full roller rockers ????:cheers
 

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Well those are steel roller tips, right? The advantage of full rollers would be in reduced friction (needle bearing fulcrum instead of the pivot ball) and reduced mass. It'd be up to you to decide if the benefit would be worth the cost. If you do decide to go with full rollers, make sure you get a good quality brand like Scorpion or Harland Sharp. A broken rocker "at the wrong time" can be catastrophic. If they haven't already been changed, I'd also recommend swapping out the Pontiac "bottleneck" rocker studs for bigger/stronger 7/16" studs. The bottleneck is a weak point and they've been known to break there, especially if you go with "more" cam that needs stronger springs.

Bear
 

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X2 on the rocker studs. Straight big block Chevy studs are the way to go. Did that to my anemic #15 heads on the '67 for insurance.
 
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