well, about a week ago, the 'ol LG4 dropped a cylinder. so i bought a 350. i am really strapped for cash so i decided to temporarily use the 305 heads on the 350. here is my question. i always thought the head gaskets for the two heads were exactly the same besides valve and combustion chamber sizes, but now lookin online at the autozone.com website, i see different part numbers for the 305 head gasket and the 350 head gasket. do these numbers relate to THICKNESS of the gasket or to some other difference? if it is just thickness, which one should i use? the thicker one i would presume...thank you for all of youe help. BTW, the Camaro is using its ORIGINAL 86 305, and the motor i got is from a '77 K10...i have the original 820 casting heads, but they are damaged, as someone dropped something into the carb and the motor was started...so a valve is damaged...i may fix these later and do a lot of port work, but for now this is my daily driver and i NEED it, i dont have time or money to deal with the 350 smogger heads...

thanks in advance everyone!!
Josh

 

The difference is the bore diameter.

Use the 350 ones. The 305 fire rings may hang over into the bores.

 

And get things spotless on both the head and block sealing surfaces. Brake parts cleaner or other non-residue solvents are the thing to use. When you think it's clean enough, clean it one more time. This is the most critical, abusive environment a gasket faces and getting a clean seal is vital.

I also share your sentiments about Ft. Lewis. Have you patrolled Yoda's Basement yet?

 

thanks for the help! can't say im too familiar with Yoda's basement though, enlighten me?

Josh

 

When I was there for some pre-commissioning school, we had a 9-day field problem with a lot of patrols. The area was really thick with big trees, exposed roots, deadfall, mud, and dense undergrowth. It slowed movement, made noise, generally felt like walking through a crowd of people grabbing at you and your equipment.

The Ranger instructors referred to it as Yoda's Basement so the name stuck w/ me.