I've got a 1974 plymouth roadrunner that I bought when I was 18. Done nothing but research so far. Found out the car was a 318 car but now has a 360 underneath. After discovering no compression I pulled and disassembled motor. I've checked my casting numbers and here goes... its a 1977 block with the original crank and one original head. But the other head is a 1975 of of god knows what. Found the compression ratios for both and want to know if I can make the work maybe with porting milling and valves? One is a 4027596 (original to motor) 66.0-72.5cc and the mismatch is a 3769974 with 65.0-73.0 cc. Any help is great! If I sound stupid sorry I'm 22 and this is my first classic build but I have a great passion for cars and an open mind to any suggestions.

 

Well we will see I've sent the heads to a machine shop today to be cc'd, tested, cleaned and have a valve job. So if you are interested in finding out if this can work keep checking back. Guess I'll be the test subject lol.

 

Hi bud! Also a 74 owner. dont have info for you on the heads, but please keep us informed.

 

Lol well doesn't really matter! Got the worst call Tuesday.... BOTH heads are cracked oh well found a motorhome 440 with 727 for $200 bucks!!!!