is there really a difference in these heads casting # 10128374 and 10125374
they both are aluminum and for an lt1 i hav the 10125374 to go on my 95 trans am (350) but was told i need the 10128374. could someone please tell me whats the difference and will they work. they said something bout reverse flow cooling i also need some roller rockers for the 10125374 if they work but need to know what kind of car they came off of. won the heads of ebay

 

Are those casting numbers or part numbers? There is a difference.

 

there is 3 casting #'s or three different heads, all will work but 2 of 3 three are a little thicker and are better for porting

 

Seeing as it is just one digit different and a 5 and 8 are pretty similar I wonder if the casting is just a little crappy and you are missreading it????


I know on one set of heads I mistook a 3 for an 8 because the casting was funky.

 

The reason why i ask is because the OP said he got these heads off of ebay. The 10125374 was a GM part number for an aluminum Corvette GenI SBC head, if I'm not mistaken.......