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Discussion Starter #1
What is the maximum RPM on a 1967 400 motor in the GTO without risking breaking something.

:confused
 

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yep Pontiacs are not high revers, with stock internals you want to stay below 5400 RPM, with forged rods and pistons they will push 6K and above if built right. Cam is the determining factor to make sure all your power comes on in the correct rev range and the beauty of our pontiacs is they make a ton of torque down low and can keep it coming right up to that 5000RPM and Torque equates to HP. If you have lets say a cam that makes its power from 4000-6500 RPM in a stock motor you are never gonna see the end of its power band, where as if you have a cam that makes its power from 2500-5000 RPM you will be right in the sweet spot when you call for it.
 

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Discussion Starter #4
Well, I guess I better be careful. I gotta a 6000 RPM chip in right now..............
Bought the car the way it is in regards to internal parts so I am not sure what all internals have been done. I've added an MSD ignition, new MSD distributor, Blaster 2 Coil, New Edelbrock intake, New Holley 650 DP, Added Electric Fuel Pump. This thing runs great but I'm sure if I keep going the way I am I will break something.

I thought I should be able to Run 5200 to 5500 though.... Not really sure.
 

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have you bounced it off the chip at 6000 yet?? you should be good at 5500 with a 400, smaller crank journal allows for better oiling than a 455 and the week point in Pontiacs is the rods not so much the crank. Only thing worse than a rev limiter set to low is blowing up your motor because it was set too high....;) set it where you feel comfortable. I really don't think my 462 ever seen north of 5000 even when driving hard but i have a 2:56 rear end, if you have a smaller (3:55+) it will get there a lot quicker, its all a balancing act, thats why what works for Chevy's will not work well with Pontiacs, and why cam and rear end choices should be tailored to the way you plan on driving it most often. Picked up a perfectly good 455 cheap because the guy said it did not make any power, pulled out a huge lopey cam the previous owner had installed that made power to 6800 rpm and put in a .545 lift with smoother idle that topped out around 5000RPM and it screams on the street now and will still roast the tires whenever my foot sees fit up to 25MPH roll.
 

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Discussion Starter #6
I have bounced it off the 6k a couple of times. I am going to put a 5500 RPM chip in.
 

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If it were me (and I drive a stock '67 400 in my convertible) I'd go no higher than the factory spec'd 5200 rpm redline. Not with a stock rotating assembly (rods)...
 

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If it were me (and I drive a stock '67 400 in my convertible) I'd go no higher than the factory spec'd 5200 rpm redline. Not with a stock rotating assembly (rods)...
:agree What he said --- key point being, not with stock rods :eek:

Bear
:agree I'm with those guys. And like Instg8ter, my 462 hasn't seen north of 5000 either.....
 

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The thing of it is, to those of us who are 'in the know' about Pontiacs, there is NO NEED to rev the snot out of one. They produce plenty of power at lower RPM's, unlike many smaller engines. (Chevy/Ford small blocks)
 

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Even with a my engine being balance and blueprinted with both forged rods and pistons I have set my rev limiter to 6K even with it being able to go higher just to be safe.
 

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Discussion Starter #13
The car did not have a rev limiter until I put the MSD box in. I'll change the chip out to the 5200 rpm chip. The cam is an Erson TQ20H single pattern cam. RPM range on it is 1200-4500.

This winter I will break the motor down to see what all I have but for now with the summer here and great driving weather I didn't want to take a chance of breaking something.

BTW, anyone going on the Power Tour. I was going to pick it up in Sweetwater Oklahoma.
 

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Discussion Starter #14
Jeff,

Always values and appreciated your input. I'll try to keep her under the 5200 rpm (with the chips help) and under 130 MPH................

Dang, I love this car.................
 

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ThBTW, anyone going on the Power Tour. I was going to pick it up in Sweetwater Oklahoma.
Dude!!! I am, and I'm picking it up in Miami... All the hotels were full in both Miami and Sweetwater though, so I'm staying in Joplin the first night and Perry the second night... how about you?

Bear
 

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Discussion Starter #17
Putting a 5200 RPM chip in it tomorrow. Will have to test drive it this weekend............

:lol:
 

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Discussion Starter #18
I'll just be picking it up in Sweetwater, spending the night then on to Arlington the next morning.

If anyone's interested I'm always up for a cold beer and to talk GTO's.......
 
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