Engine stud sealant required ?

Turbo6inKY

Short Guy
Jun 18, 2001
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blog.andrewdscott.com
Having never dealt with that specific block, you can answer your own question with any block: Shine a light down the holes. Are they blind or do they go into the water jacket?

Anything going into the water jacket needs sealant. Anything going into a blind hole gets ARP lube.

The countersink is to slope and center the fastener into the hole to prevent cross-threading. It also removes a sharp edge that can become a place for a crack to start.
 

ek02

Well-Known Member
Jan 31, 2008
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Use Permatex thread sealer 59235 on the studs.If you use the 109 studs on a 4.1, you may need to use double washers on the studs. ARP sells them in sets or you could countersink the bolt holes which is what I do. I have seen 4.1 blocks that had one side countersunk and the other side not countersunk.
 
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jason mizel

New Member
Nov 20, 2007
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Thanks guys I didn't get the holes countersunk so will double washer some of the ones that are close to the bottom of the threads. I kinda like having the extra threads by not having it machined that way. But is there anything crafty I can do to the sharp edge at the top there to alleviate the stress there or should I not worry too much about it at this point? Going to run a 4.020fel1000 gasket at about 110-115lbs on a 3.997 bore
 

earlbrown

runs with scissors
May 26, 2001
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Yes, you need sealant. On, your deck surface (and your heads deck surface) bevel the shit out of the hole to spread the clamp load out and away from the threads themselves.

Also use your head gasket as a template to drill steam holes in your heads to let the air pockets out of your siamesed bore block.

The 3.8 bolt kit won't work. The studs will be too long. You need the correct ones for your block that doesn't have the countersunk holes. I think ARP lists it for the 8 bolt stage 1 block (it's been a while since I bought mine)
 
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jason mizel

New Member
Nov 20, 2007
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Yes, you need sealant. On, your deck surface (and your heads deck surface) bevel the shit out of the hole to spread the clamp load out and away from the threads themselves.

Also use your head gasket as a template to drill steam holes in your heads to let the air pockets out of your siamesed bore block.

The 3.8 bolt kit won't work. The studs will be too long. You need the correct ones for your block that doesn't have the countersunk holes. I think ARP lists it for the 8 bolt stage 1 block (it's been a while since I bought mine)
So I'm using the 3.8 stud kit #123-4003 but being told they're too long sounds strange to me because in order to see if the studs would be too long in a way that the nut would potentially bottom out or run out of threads I first screwed them in. I then measured the depth of the holes in the head and then marked on the studs where they would begin sticking through the head and seemed that there were plenty of threads there left before the nut would bottom out. There were some that were a little closer to the bottom of the threads than the others and those were the ones I was going to use double washers on. Would I need to get the 123-4001 kit for the production block, I wanna say my 291 block is from 1983 but not 100% sure on that.
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ek02

Well-Known Member
Jan 31, 2008
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The 123-4001 will probably work, but since you have the 123-4003 and it looks like there are enough threads showing below the head, use them with a double washer on the tall studs. I have Champion GN1 heads on my 4.1 and I had to buy 2 sets of studs and mix and match them. The two middle studs have double washers. The studs recommended by champion were too long.