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Discussion Starter · #1 ·
I think I may have ordered the wrong ARP head bolt kit. I have a 1968 400 with 092 D port heads off a 1966 389. I ordered the 190-3602 kit for the 389 heads. The length and style are different then the original head bolts. Any ideas?
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Looked up the ARP number and it says 1966 092-093 head, so correct replacement bolts by ARP.

The heads are different than factory and use a washer under each head. You will see the washer will have a radius that matches the radius under the bolt head - they get used together.

The ARP kit is not a factory bolt kit. You do not get the factory bolts with the threaded studs on top.

The ARP bolts use the supplied lube/moly grease (very light coating, not sloppy) on th threads to get the correct torque. The torque number is not the same as the factory head bolts, so follow the ARP torque specs and Pontiac torque sequence.

You may want to rent a thread chaser kit, not a tap. The bottom thread chaser cleans the bolt hole threads. A tap will chew them up or cut them and you may strip out a bolt. Most auto parts stores rent/have these kits for use. Blow out/clean the bolt holes BUT keep them dry. Do not use any water or liquid that might be left behind inside the bolt hole. Once the bolt had been inserted and torqued down, any liquid can become trapped and will act like a boiling coffee pot on the stove - the liquid will boil and built pressure and can have enough pressure to crack the bolt hole or block.

To verify that your ARP bolts are the correct length, insert all the bolts in the head and observe how much of the threads stick out the bottom. They should all stick out uniformly. If you have any sticking out longer or less than all the others, then something is wrong and needs to be checked. Too long and they bottom out. Too short and you strip out the holes.

No need for any sealant on the bolt threads as the Pontiac engine bolt holes are called "blind holes" as they do not go into the water jacket like other makes.

If you need to use the head bolts with the studs on top, several have said just to use those in place of the ARP bolts and there should be no issue - but use factory torque on those. I have never mixed bolts, just used the ARP bolts.

This might offer a little more info:

 

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Any reason for running the closed chamber heads on the 400? Do you have dished pistons installed? If not, depending on camshaft and valve lift, you may run into clearance issues. And if running the stock type pistons, you will need 100+ octane fuel to deal with the very high compression.
 

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Discussion Starter · #4 ·
Any reason for running the closed chamber heads on the 400? Do you have dished pistons installed? If not, depending on camshaft and valve lift, you may run into clearance issues. And if running the stock type pistons, you will need 100+ octane fuel to deal with the very high compression.
Yes Paul Carter(outstanding engine builder) set me up with correct pistons, camshaft, lifters, etc. I believe I will end up with 9.5:1 compression. Had a 66 389 but found out block was cracked and Paul already had my 092 heads. So he had a 400 block I could used. So with reworked heads, mild cam, 6:1 rockers, ram air exhaust, tri-power, and a few other things should be right at 400 hp. We'll see.
 

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Discussion Starter · #5 ·
Any reason for running the closed chamber heads on the 400? Do you have dished pistons installed? If not, depending on camshaft and valve lift, you may run into clearance issues. And if running the stock type pistons, you will need 100+ octane fuel to deal with the very high compression.
Thanks so much for the help.
 

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Yes Paul Carter(outstanding engine builder) set me up with correct pistons, camshaft, lifters, etc. I believe I will end up with 9.5:1 compression. Had a 66 389 but found out block was cracked and Paul already had my 092 heads. So he had a 400 block I could used. So with reworked heads, mild cam, 6:1 rockers, ram air exhaust, tri-power, and a few other things should be right at 400 hp. We'll see.
Thanks! With Paul Carter doing the work and figuring out the combo, you won't have any issues. He has a great reputation for powerful, long-lasting engines.
 
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