#1 problem with the 403 olds is the compression. Stock is 7:9:1...your bore it..it gets even worse. Can't do much w/o compression. Early heads or piston swap. Most people do not realize the 403 olds is a very low compression motor in stock form. Bolts ons are not going to do a thing for this motor. Cam...headers...ect. Waste of money. The money should be spent on heads ~60cc or pistons that are flat top and not dished.
A simple rebuilt 403 will make 200HP max. Cam swap....maybe 225max. A VTEC Honda 4cylinder makes more HP than a 403 stock these days.......
olds
|