sbolds heads

[87oldssalon302sbc]

I have a 403 that i'm tring to decide what heads to run.The engine was rebuilt not long ago,with all stock except cam.Recently I decided to try and find a better set of heads.In the past I had asked about the #3 330 head,now I found a set of the #7a 350 heads.I,m realy not looking for a drag racer just playing around.I have the rpm intake and cam for this setup,I would like to use the 403 valves as they were new when I rebuilt it.I'm putting it in my 87'salon.All and any opinions welcome.

 

[hunter_alexander]

That is the same setup I am going to be going with in my 403 build. I have a set of 7a 350 heads (1972 vintage), RPM intake.

Do you remember how far in the hole the pistons are when you rebuilt it last? That along with cc'ing the heads will help you determine what compression ratio you will come up with. Well, that and head gasket compressed thickness.

Depending on what compression ratio you end up with will determine the cam you should run.

I am doing the same as you though, taking the vavles from the 4a heads and putting them in the 350 heads.

Sounds like your on the right path though. Let us know how it goes.

 

[87oldssalon302sbc]

c.r.

That realy don't matter,anythings better than the stock 403s soup bowl piston mixed with the 83cc head.The 7a is supposed to have a 64cc chamber,according to olds faq's web page.That shoud give the 403 a major boost in pep alone,I just can't see not getting some more from the engine after studying the bore and stroke.The pistons are around .030 give or take a few,as far as I know its the same as what the factory setup.Some replacement pistons are .020 farther down than stock,but the ones I have seem to be the same as what olds installed.