Radiator

[olds307 and 403]

The Champion 4 core has been proven to cool even a 10 to 1 403 but it is huge. A large 2 core rad is best but the 3 core may do the job, hopefully it does.

 

[Supercharged111]

The Champion 4 core has been proven to cool even a 10 to 1 403 but it is huge. A large 2 core rad is best but the 3 core may do the job, hopefully it does.

Yeah, I should clarify I don't mean to say the weird Chinesium 3 cores aren't better than stock, they're just not as good as they could be.

 

[eric_cspan]

Let me know if you need help or end up switching. I can offer a deal on one.
Like others have said, oversize two row models with at least 1" tubes will outcool any 3 or 4 row aluminum.

 

[fleming442]

72 olds 350 30over 9.5to1 comp cam 7a heads switched to adjustable rocker arms around 375hp

TRW/Speed Pro pistons....?

 

[olds307 and 403]

TRW/Speed Pro pistons....?

I would assume the 5.8cc dish variety. It must be a pretty aggressive cam to hit 375 hp, curious on its specs as well.

 

[Rocket350olds]

Speed pro pistons and comp cam high energy series

 

[olds307 and 403]

I assume the 218/218 cam. Any porting or bigger valves?

 

[Rocket350olds]

Chevy valves and studs with ford rocker arms making them adjustable

 

[olds307 and 403]

Really? I would guess 2.02/1.60 valves? I didn't realize those could be made to fit. Most use the W31 1.995/1.625" valves.

 

[fleming442]

Speed pro pistons and comp cam high energy series

Do you recall the piston to bore clearance? TRW recommends .0025-.003, but they need more, like .004. It's a common problem on Olds motors with those pistons. If the engine is too tight, all the radiator in the world won't cool it down.