possible engine swap for a Cad with an Olds 307 V-8

[Maynard Krebs]

For those who have, or might buy, a RWD Cadillac that was originally equipped with an Olds 307 V-8, how difficult would it be to install an Olds 350, or preferably an Olds 403?   These are all the same Olds block:  just different bore.   

My guess is that it would be a lot easier than to try putting a SBC in such a car. 

[TJ Hopland]

You are correct that the basic block of the Olds V8's never changed.   The 'big' motors like 425 & 455 just had a taller deck height but still was the same length and same mount locations.   

This would make the bolt in part and easy swap.   Not sure what you would run into electric wise.   A stock 350 may run ok on the same carb and timing .   If you were going for a more built engine I would guess you would need to mod or replace the carb and would have to investigate timing options, not sure if anyone would do a 'chip' for these or not.     If you just ditch the computer stuff what would you loose other than the torque converter lockup?   Maybe nothing?   There are reasonably priced aftermarket ways to deal with the torque converter.  Even decent options for EFI now.         

[Ken Perry]

I did a 88 Fleetwood,put a 403 with a little cam,same intake and carb,just changed the rear meatoring rods. Anyway when it was done it passed strict California smog laws. Went from wimpy slow turd, to smokin the tire of the car. Bad thing with 403 Olds,they only like to be bored .020 over. Makes a nice car a good car    Ken Perry