Could I fit a 403 in a Regal? It currently has a 3.8L 231 in it, but I'm looking for something with a little more pep to it. If so would it be hard and would I spend a good amount of money making the switch.o No:
403 (olds motor) Yes the 403 is a small block olds motor like its brother the 307 that was optional in your regal. You will have to change the motor mounts. All the engine accesories are different. A more buick friendly swap would be a 350 buick engine. The 350 will use the same enigne mount locations as the 3.8 and many of the engine accessoryies too. This would be a cheaper way to go as far as the swap cost go. You will need to modifiy the exhaust, but you probably want to run duals anyway. Jake
check this site out http://members.cardomain.com/regal403 This young man left a comment or 2 on my site and when i went to look at his car that exactly what he has.he may help in this swap.