�66 small block timing cover gasket set recommendation wanted

[Gary B.]

[Peter H.]

[Joe L.]

Does anyone have a recommendation for a high quality, but less colorful alternative to the bright blue Fel-Pro timing cover gasket set for a ‘66 small block?

Thanks,

Gary

Gary------


Easy. Mahle #T27781. Gray/black in color.

The last available GM gasket (now discontinued without supersession) was GM #12369488. However, it was just the Fel-Pro blue gasket in a GM package with a GM part number.

[Gary B.]

[Joe L.]

Thanks guy.

Joe, I think there are two version of that gasket from Mahle: a paper version, 27781; and a composite version, 27781VC for $8 or $10 more. Any thoughts about the composite vs paper?

Gary

Gary------


I have no doubt that the composite version is better. However, I don't know how thick the composite gasket is. For the timing cover, a very thin gasket is essential. Otherwise, the timing cover is spaced out further from the block and can result in interference with the waterpump rear plate. This can be dealt with by using extra thick waterpump leg gaskets but I do not recommend them, either. That can result in leaks and/or pulley alignment problems.

With the short leg waterpumps used for all 1955-70 Corvettes (and, even the short leg 1971-82 pumps), the timing cover is virtually in contact with the rear plate of the waterpumps even with the stock very thin gasket. Anything that effectively reduces the spacing between the cover and the waterpump is to be avoided.

[Gary B.]

[Gary B.]

[Joe L.]

[Gary B.]

[Joe L.]

Joe,

True. I guess I’d have to buy one of each. But usually when I buy two (or three) of the same part it’s because I’ve forgotten where I out the first one. Or the second one. But buying multiple examples of the same part has gotten old.

Gary

Gary------

The original GM gasket was VERY thin. It's actually quite uncommon for GM to use a gasket this thin when the need for a seal in an oil lubricated environment exists. I suspect they would have used a thicker gasket unless there was some other requirement that need to be addressed.

Attached are photos of my rebuilt original 350 with short leg waterpump. I used the GM timing cover gasket (GM #3799620), GM waterpump leg gaskets (GM #3754587), and GM waterpump rear cover gasket (GM #3782611). Note that there exists ZERO clearance between the timing cover and waterpump rear cover. Incidentally, the GM #3782611 waterpump rear gasket is also a very thin gasket. Rebuilt pumps often use a thicker gasket which is a source of problems.

DSCN3972.jpgDSCN3973.jpg

[Gary B.]

[Joe L.]

Joe,

I never paid any attention to how remarkably tight a fit that is.

Gary

Gary------


Beginning in 1969 most Chevrolet small and big block applications converted to the "long leg" style waterpumps. There were several reasons for this but, whether one was eliminating the interference problem or not, the interference problem was completely eliminated. However, Corvettes and some MD/HD trucks never converted to the "long leg" pumps. Corvettes used the short leg style pumps right through 1991.