Intake Manifold differences

[Ggmac]

Some picts of my 36 with iron heads and an aluminum intake.

2 of my 21 stud engines have cast alum intakes , one is completely burnt thru the exhaust .
The heads on both have the 46 cast date code . It's located on the underside of the head , near the intake ( top ) and is visible if you use a mirror between the intake and cyl head .
One engine is flat top std bore steel Pistons the other is domed and .040 over .
2 sets of heads with the 46 code , 2 different combustion chamber designs .
Both are LB

 

[rotorwrench]

Just for grins, I looked at the cylinder head chart in the green bible. It shows that they made the 40-6049-B iron heads for the 33 thru 36 and 68-6049-B iron heads for 1936 but in the "replaced by" column it shows the 68 series with the B suffix iron heads for all the early water pump in head 21-stud engines. Those part numbers 68-6049-B & 68-6050-B were the final replacements for all those old engines. I have no idea when they quit producing them but 1946 would have been the 10-year mark that most manufactures go by for replacement part production limits.