olds swap sb to bb

[buold]

No matter which engine I end up with the plan is idle to 5500 power range.

So which engine would u guys use?

 

[Vern]

Either but probably the 455 as more cubes equal more torque at a more useable & reliable rpm. Generally they are also more commonly available and commonly know for a build up. If you are not stuck on brand specific I found a Cadillac 500 for dirt cheap and its about the same work as putting in a 455. BTW if the 403 has an advantage it might be that it is easier to fit in a gbody with cheap headers. 455 headers are expensive but Kooks has them and they are quality. The Sanderson 600 headers for the Cad are also suppossed to fit the gbody. I had mine built. Check out www.robertpowersmotorsports.com for an excellent street car build up. Bob ran like 12.3 at 110 and got 15mpg before his car was stolen and that is on pump gas, with AC, power steering, & power brakes.

 

[olds307 and 403]

Get a better cam,intake, headers and exhaust. Swapping 330 1,2,3,4 and early 350 5,6,7,7a heads will give you low 9 to 1 comprssion with Corteco gaskets. These heads flow better stock on the exhaust side than your 4A heads. Unless you get a 455 for a steal, you will have to pay for the core on top of a rebuild.