396-427 GM Steel Shim Head Gaskets

[James W.]

Can you use the same GM NOS steel shim head gaskets p/n 1-330860 or 3863199 on both a 396 or 427 engine? Why I ask is that I have a 396 bored out to a 427.


Thanks,

James

[Joe L.]

Re: 396-427 GM Steel Shim Head Gaskets

Can you use the same GM NOS steel shim head gaskets p/n 1-330860 or 3863199 on both a 396 or 427 engine? Why I ask is that I have a 396 bored out to a 427.


Thanks,

James

James------


The GM #330860 can be used on any 396, 427, or 454 engine.

The GM #3963199 can be used on L-78 396 engines as well as all 427 engines. GM advises that it should not be used on other 396 engines but I really don't understand why.

[James W.]

[Joe L.]

Re: 396-427 GM Steel Shim Head Gaskets


James-----


GM #3876198 was the original gasket set. GM #3955527 replaced it and was the last available gasket set.

[James W.]

Re: 396-427 GM Steel Shim Head Gaskets

Joe,

Thanks again for the information.

James

[James W.]

[Joe L.]

Re: 396-427 GM Steel Shim Head Gaskets

Joe,

I’ve got one more question. What is the difference between the 3955526 gasket set and the 3955527 gasket set?

Thanks,

James

James------

Good thing you asked. I erred in my previous post and I've corrected it. The GM #3955527 is the correct gasket set for the SHP application. This gasket set has the rectangular port configuration. The GM #3955526 has the large oval port configuration applicable to 1966-72 L-36, L-68, and LS-5.

[James W.]

Re: 396-427 GM Steel Shim Head Gaskets

Joe,

What is GM intake manifold gasket set part number 12511789 used on?


Thanks,

James

James------

Good thing you asked. I erred in my previous post and I've corrected it. The GM #3955527 is the correct gasket set for the SHP application. This gasket set has the rectangular port configuration. The GM #3955526 has the large oval port configuration applicable to 1966-72 L-36, L-68, and LS-5.

[Joe L.]

Re: 396-427 GM Steel Shim Head Gaskets

Joe,

What is GM intake manifold gasket set part number 12511789 used on?


Thanks,

James

James------


GM #12511789 replaced GM #3955528. It's application is 1969 L-88. It has the rectangular port configuration. If I recall correctly, it differs from the SHP gasket set by having a blocked heat crossover.

[James W.]

Re: 396-427 GM Steel Shim Head Gaskets

Thanks again Joe. I'm still looking for an acceptable set of '65 396 engine intake manifold gaskets for flight judging.


Regards,

James

James------


GM #12511789 replaced GM #3955528. It's application is 1969 L-88. It has the rectangular port configuration. If I recall correctly, it differs from the SHP gasket set by having a blocked heat crossover.

[James W.]

Re: 396-427 GM Steel Shim Head Gaskets

Joe,

Will either of the eBay listings the first being GM part number 12511789

https://www.ebay.com/itm/NOS-70-66-67-68-69-Corvette-Camaro-GM-454-396-427-Square-Intake-Manifold-Gaskets/302610032481?_trkparms=aid%3D222007%26algo%3DSIM.MBE%26ao%3D2%26asc%3D47300%26meid%3D386d9750f2cf45a68cedbf06d26cba50%26pid%3D100005%26rk%3D1%26rkt%3D6%26sd%3D112393604489&_trksid=p2047675.c100005.m1851

The second eBay list GM part number 3955527

https://www.ebay.com/itm/NOS-65-66-67-68-69-Corvette-396-427-Rectangular-Port-Intake-Manifold-Gaskets-70/112393604489?fits=Model%3ACorvette&hash=item1a2b2e4d89:g:BFUAAOSwiBJaHHPB&vxp=mtr

Thanks, James

Thanks again Joe. I'm still looking for an acceptable set of '65 396 engine intake manifold gaskets for flight judging.


Regards,

James

[Carl N.]

Re: 396-427 GM Steel Shim Head Gaskets

James------


GM #12511789 replaced GM #3955528. It's application is 1969 L-88. It has the rectangular port configuration. If I recall correctly, it differs from the SHP gasket set by having a blocked heat crossover.

Agree, Correct

[Joe L.]

Re: 396-427 GM Steel Shim Head Gaskets

Joe,

Will either of the eBay listings the first being GM part number 12511789

https://www.ebay.com/itm/NOS-70-66-67-68-69-Corvette-Camaro-GM-454-396-427-Square-Intake-Manifold-Gaskets/302610032481?_trkparms=aid%3D222007%26algo%3DSIM.MBE%26ao%3D2%26asc%3D47300%26meid%3D386d9750f2cf45a68cedbf06d26cba50%26pid%3D100005%26rk%3D1%26rkt%3D6%26sd%3D112393604489&_trksid=p2047675.c100005.m1851

The second eBay list GM part number 3955527

https://www.ebay.com/itm/NOS-65-66-67-68-69-Corvette-396-427-Rectangular-Port-Intake-Manifold-Gaskets-70/112393604489?fits=Model%3ACorvette&hash=item1a2b2e4d89:g:BFUAAOSwiBJaHHPB&vxp=mtr

Thanks, James

James-----


Either of these gasket sets will work fine. However, the 12511789 will need to have the stainless steel plates blocking the heat crossover removed. Contrary to what the seller says, this gasket set was never cataloged by GM for L-78, L-72, L-71 or LS-6 applications. Of course, it can be used for those applications with the cross-over plates removed. The configuration is correct.

I don't know what color side gaskets are currently "in vogue" with respect to originality. I have some original big block gasket sets [none for sale] which date from the mid-to-late 60's and they are dark gray or black.

One thing to keep in mind is that GM never manufactured any intake gaskets. They were manufactured by Victor, Detroit Gasket, McCord, and, perhaps, others. In fact, if you look closely at the 12511789 you will note the Victor Gasket logo. If you look closely at the 3955528 you will note the McCord logo. Those manufacturers have offered and still offer virtually identical gasket sets. The one "big" difference is that the end seals don't have the "GM" logo. So, when one pays "big bucks" for these gasket sets, what one is really paying for is the "GM" on the end seals. Would I do that? Not a chance.