Head gasket selection

Daca214

Daca214

Master Mechanic
Dec 1, 2017
284
196
43
Jupiter, FL
#1
Hey guys quick question. I just discovered my olds 307 was bored .040” according to marking on pistons

How can i select the proper head gasket? I cant seem to find anything on fel-pro other than the stock selection. Will that work?
 
pontiacgp

pontiacgp

Canadian Prime Minister
Mar 31, 2006
23,564
4,262
113
Kitchener, Ontario
#2
The 350 I have is .030 bored and I just changed the heads this year. I used the stock Felpro head gaskets.
 
B

bracketchev1221

Greasemonkey
Jan 18, 2018
222
129
43
#4
Usually the replacement head gaskets are made to accept a large overbore and are made to fit the cylinder head chamber. For example, the big block chevy replacement gasket is 4.37 on a 4.25 bore.
 
olds307 and 403

olds307 and 403

Comic Book Super Hero
Oct 14, 2008
3,446
820
113
Melville,Saskatchewan
#5
Yes, the Felpro is the only currently available gasket available for the 307 that I know of. The 260, 307 and 403 have unique head gaskets due to oddball bore size. The head gaskets changed in 1977 and up motors, a 3A head 350 gasket might work but why even try unless you are going for a huge overbore, which supposedly a 307 can take. How far in the hole do those pistons sit? I know it is just a 307 but it may have miserable low compression and terrible quench.
 
Daca214

Daca214

Master Mechanic
Dec 1, 2017
284
196
43
Jupiter, FL
#6
Yes, the Felpro is the only currently available gasket available for the 307 that I know of. The 260, 307 and 403 have unique head gaskets due to oddball bore size. The head gaskets changed in 1977 and up motors, a 3A head 350 gasket might work but why even try unless you are going for a huge overbore, which supposedly a 307 can take. How far in the hole do those pistons sit? I know it is just a 307 but it may have miserable low compression and terrible quench.
I havent checked that yet, but will. I just learned about Quench on Petes Garage on youtube........LOL. This should be interesting
the compression was around 160 all around before i took it apart and found the worn pushrod on #8. i believe the lifter was frozen
 
Daca214

Daca214

Master Mechanic
Dec 1, 2017
284
196
43
Jupiter, FL
#7
thank you all for your replies. I feel comfortable going with the Fel-Pro's
 
olds307 and 403

olds307 and 403

Comic Book Super Hero
Oct 14, 2008
3,446
820
113
Melville,Saskatchewan
#8
Actually 160 is pretty good.
 
P

paul.m

Greasemonkey
Oct 20, 2018
123
46
28
#9
This is also a chance to increase your compression ratio if your interested , i wont try to type out all the per tenant info here but im sure theirs a ton of info on you tube. Just in case you were not aware of that . And fel pro,s will be just fine .
 
Thread starter Similar threads Forum Replies Date
M General Discussion 3
SoFloG General Discussion 3
SoFloG General Discussion 5
pontiacgp General Discussion 20
Rudy913 General Discussion 8

Similar threads

Please support GBodyForum Sponsors

Classic Truck Consoles Dixie Restoration Depot Mike's Montes P-S-T Southside Machine Performance UMI Performance

contact [email protected] for info on becoming a sponsor