ok so i have been reading up on the 403 engine that i amgoing to put in my 85 cutlass supreme and ran across another forum talking about all the things someone did to there 403 amd they said 350 olds heads (7a) so if that is the 350 olds head number then i must already have a 350 olds in my cutlass because thats what head numbers are on my "307" can someone please tell me the truth of this or is it way off
head #s
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You do have 7A heads, but they are the wrong ones. The ones on the 307 have a 7 with the A being the same size as the 7. The 350 heads have a 7 with a smaller subscript A, the letter will be around a 1/4 in tall.
not sure if the a is the same size or not but i will have to check it also is there a way to find out what size the motor is with the block number a just checkin would it be the series behind the water pump
The numbers behind the w/p will tell you what size it is. Post the numbers and someone will let you know.
brethenry_08 said:
Yes, it's confusing because as others have noted, Olds used the 7A designation twice, once in 1972 and once for the roller cam 307s. These are not the same castings!. To avoid confusion, look for the casting number above the center two exhaust ports. The 1972 heads have casting number 409147. The 1980s heads have casting number 0142.
4790GM50LG so here is the numbers that are behind the water pump so can someone please tell me which motor i have????
what numbers do i need to look at to see which motor my new one is i was told that it is a 403 but i wanna make sure in case its a 350 or 455 or just something different than a 403
Olds motors should have the inches cast in big numbers on the bottom of the block. Just crawl up under there with a flashlight. I forget which side its on, but it should be there....
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