Where are the casting numbers for small block cylinder heads?
Casting numbers for small-block cylinder heads are usually located between the valve spring seats under the valve cover for Gen I and Gen II heads and in the valve galley on the newer cylinder heads.
What do the numbers mean on Chevy cylinder heads?
GM uses a letter code to represent the month when casting the date of manufacture into the cylinder head. For example, a casting number B139 represents: B = February (A= January, B= February, etc.) Chevy heads have often been identified by sight and most commonly by the different casting shapes on the ends of the cylinder heads.
When did SBC start using low compression cylinder heads?
Casting 3836842 was used on 238ci V8 engines from 1957-1967. These low compression heads came with 1.72-inch intake and 1.5-inch exhaust valves and a 59cc combustion chamber. The intake runner volume measured 137cc.
What’s the difference between 305 heads and 350 heads?
These heads will port out well, but be aware that 305 heads have smaller valves, so only look for 350 heads unless you’re specifically working on a 305. This will save you the expense of extra machining to put in larger valves.
Casting numbers for small-block cylinder heads are usually located between the valve spring seats under the valve cover for Gen I and Gen II heads and in the valve galley on the newer cylinder heads.
GM uses a letter code to represent the month when casting the date of manufacture into the cylinder head. For example, a casting number B139 represents: B = February (A= January, B= February, etc.) Chevy heads have often been identified by sight and most commonly by the different casting shapes on the ends of the cylinder heads.
What should the grind be on a Type 4 head?
On a Type 4 head, VW specified 15/30/75 for the intake valve seat and 15/45/75 for the exhaust valve. You might end up with a 20/45/60 grind because those stones are more readily available for their tooling.
Casting 3836842 was used on 238ci V8 engines from 1957-1967. These low compression heads came with 1.72-inch intake and 1.5-inch exhaust valves and a 59cc combustion chamber. The intake runner volume measured 137cc.