what heads part numbers for 67 350

[hrascoll]

my car is a 67 350 rs/ss was born 1st week of april 67. what are the correct head casting numbers for my 350. is it considered early or late?  so far it could be 3917291 with out temp sending drilled for early/late or 3890462 for very early. I have heard of some 291's with cast dates in march. this is very important to me as my block is correct with a cast of C137 and 3892657 and vin. thx howard

[z28z11]

Colvin states in CBTN that the 3890462 head was used from January 1966 through May 1967 . The 3917291 head was released in March or April 1967 with some minor use overlap (the dates aren't clearly defined). The 291 heads from March or April will have the sending unit boss present, but drilling and tapping for the sending unit did not start until May or June 1967. All 1968 applications using the 291 heads (350 and 302 w/ 2.02/1.60"s) had the sending unit location finished for the sending unit.

Close as I can research - I have two sets of 291's, both are late '67 and both are drilled/tapped.

Regards,
Steve

[MO]

I'd say the 462's would be better for a March built engine.

[hrascoll]

thx for the replies! I have the cbtn book and also read about the release dates. is it possible that new production 291's made it into late march built engines?   to me I would assume not and gm was trying to reduce inventory of the 462's. so I would lean toward the 462's also. but it is complicated because of the change over dates.

[MO]

I have a close date to yours and it came with 462's.

[hrascoll]

thanks for the reply