oldstoro66

Hi to all, it's been awhile since I joined. I have a 66 Toro, but it has a California 425.....Heads have been changed,who knows what else? It's a pooch to say the least. But a good parade car! I have removed the smog stuff,plugged the head holes. So now,do I rebuild the 425(heard it is more expensive than a 455?) or look for a runnable 455 and eventually redo it?

Gerald Nickels

More cubes in a 455 and higher RPM in a 425 Olds. I would take the insides from a 425 and install them in a 455 engine. More cam selection in a 455block than a 425 Olds motor. I like 425 better.

Oldsmaniac

The 66 Toro 425 (large lifter) and 455's have the same cam bank angle. Cams interchange. If you put the 425 internals in a 455 block you have a 425. The cost is basically the same to rebuild either. I would stick with the 425.

Tedd Thompson

Or if the rings and bottom end is still in good run able shape just add some early heads a set of lifters and a better cam. Lot less money if that is a concern.. Just my thoughts..... Tedd

cutlassefi

Not sure why you guys insist the 425 will wind higher than a 455 right off the bat. More internet crap.
Compare the factory hp/tq ratings of a 425 and a 455. Does the peak hp or tq happen at a higher rpm on a 425 vs a 455? The answer is no. Olds heads aren't great, that has more to do with it than anything.
The only thing that's less money on these two is good pistons for a 455. It has more choices but you can still get aftermarket rods for a 425, as well as .921 lifters, or cams done for a 45* lifter angle if so equipped.

oldstoro66

Thank you to all for your help...I can tear an engine down,& put one together, but I do not have the knowledge to rebuild it..Cam angles/lifters/cam timing, crank lead etc... I need help...I'll be back...