302 Chevrolet Engine Build

[Nmbr1GMfan]

Very cool! Lots of great members here that's for sure.

[Greg Reimer 7376]

Great looking engine build, but don't use OEM small journal rods. They break where the big end and the beam connect at the flare. Get the Manley rod or something else. The 67 engine DID use a 2 bolt main 327 4" bore block and a steel small journal 283 crank, so the assembly was very light for an OEM configuration. Also, do your early 462 heads have 2.02 intakes and 1.600 exhausts? I have a pair of those on my core shelf, and the rocker studs are cross drilled through the stud bosses with little roll pins through them and the studs. Only motor I ever saw like that were 62-65 hi po 409's. I wonder now if that is what these heads I have originally came on, if not a 68 325 horse 327. Very interesting engine build you have here.

[Hacksaw]

Originally Posted by Greg Reimer 7376

Great looking engine build, but don't use OEM small journal rods. They break where the big end and the beam connect at the flare. Get the Manley rod or something else. The 67 engine DID use a 2 bolt main 327 4" bore block and a steel small journal 283 crank, so the assembly was very light for an OEM configuration. Also, do your early 462 heads have 2.02 intakes and 1.600 exhausts? I have a pair of those on my core shelf, and the rocker studs are cross drilled through the stud bosses with little roll pins through them and the studs. Only motor I ever saw like that were 62-65 hi po 409's. I wonder now if that is what these heads I have originally came on, if not a 68 325 horse 327. Very interesting engine build you have here.

The 302 had a special 3" stroke crank, not a 283 piece. You can check the date code on your 462 heads, some had 1.94 intakes. The small roll pins were an early common fix to prevent the press in rocker studs from pulling out.

[Greg Reimer 7376]

Got motivated today, rolled my wagon out a bit to access the cylinder head rack, pulled out both those 462 heads, one has a date cast of H 6 6, the other one looked like H 12 6. Rather early castings for 462's, but they definitely have 2.02 intakes and 1.60 exhausts. I haven't taken them apart to inspect anything, but they were kind of interesting.

[Hacksaw]

Originally Posted by Greg Reimer 7376

Got motivated today, rolled my wagon out a bit to access the cylinder head rack, pulled out both those 462 heads, one has a date cast of H 6 6, the other one looked like H 12 6. Rather early castings for 462's, but they definitely have 2.02 intakes and 1.60 exhausts. I haven't taken them apart to inspect anything, but they were kind of interesting.

Greg: If there is no provision on the side of the head for the water temp sensor, then these could pass for 67 Z heads. Aug 6th and 12th 66 castings.

[Greg Reimer 7376]

Interesting. I will check this weekend for the water temperature boss and the threaded hole. Winder if these came on a 327 350 horse or even a '68 325 horse 327. When did the screw in studs and push rod guide plates come along?

[Greg Reimer 7376]

Well, curiosity being what it is, I got back out there and checked. No coolant temperature switch hole,no provision for one. I checked the other two pair of cores I have, none there either. I then went into the trailer, opened the hood on my race car, no temperature switch holes or boss for one on them either. Now, heads made in 1968 had them, as the 3917290 and the 3917293 castings, which are '68 only, do have a plug or a water temperature switch opening. Seems that '68 was the year stuff like that started changing.