Today I went and looked at a set of heads and intake that was taken of my car back in 1982 when it went through a frame off. Note: My block is a matching numbers cast on may 12 66 and stamped may 20 66. It was built in Atlanta. At its completion the engine still has standard bore but 375 hp heads and intake where put on. The 325 hp heads and intake that came of motor have been in a barn since. Here are the numbers: Heads 3856206 date code F 23 5 (June 23 1965) and G 7 5 (July 7 1965).
Intake 3866948 date code G 7 5 (july 7 1965). I have looked at much info and found that 3856206 were used on 1965 impala 396 and some early 1966 chevelles. Could this be possible? Could they have pulled some leftover 65 head and put them on that late of 66 block? Thanks. Wayne

I talked to the guy that did restoration today. He says heads in question where taken off my chevelle. He said engine didn't appear to have been rebuilt to best of his recolection. He thought mileage on car was in 70,000's. I also found a website offshoreonly.com that shows part #3856206 as 65-66 ovalport, closed, 396, 97cc chamber. It doesn't seem to make sense that someone would take 325hp heads and intake off , then not bore out cylinders and put 325hp heads and intake off something else and put them on. I really could use some insight because the guy that has these heads and intake is looking to sell them and is giving me first chance. Please help. Thanks Wayne

I ran a set of 206's with cast iron intake with a mild cam, and they worked great. The 206 head ran a gambit of applications, but are more typically associated with full size cars, not chevelles. the 702 usually is found on mid size apps. the likelihood of having a previous year intake on a middle year production car is very unlikely, but not impossible, although very improbable. They are a very cheap way to gain good compression being closed chamber, with such small CC's heck even the highly sought after 063 is only 99. If you need them go for it, on the other hand if you think it will make your car matching numbers, and you want them for solely that reason alone, I say pass. the fact that intake was from a previous model year alone should tell you they arent original to your ride. I also see you have a HP rating of 375 in your signature, factory? everyone wanted the square ports, and they probably got sold off at some point. good luck jason.

Jason..Could you elaborate on why the 063 is highly sought after? I bought a 69 427 that has the 063's.

they easily accept valve resizing without striking green oil (antifreeze). Anyway that comment was a bit subjective, many people look for different cast numbers for a wide variety of reasons. that particular cast number ran on 325.350. hp 396 and the lower hp 427 models for quite a while, middle of year run 68-early 70 (<-what is meant by this is dec 69).

Thanks Jason, yes the sole reason for my interest was the chance they were original to my car. I know they came off my car but I wanted to be 100% sure they were on from factory. Thanks for information. You are the 3rd person to say it is not likely they are correct for my car. I guess I'll pass on them. I now will have some loot to spend on other parts. Oh, 375hp is not factory. Block is matching numbers to car but 375hp where put on back in 1982. They have a 70 date code.