40 Olds

Ok guys, knowing that the 455 is more accessable for parts and more plentiful what is wrong with a 425 ? It has a shorter stroke, forged crank,
360 stock horses, 470 ftp of torque and it is one hell of a BB. Granted only
3 years used in vehicles but my preference is the 425 Super Rocket. My 65 was actually cast in 64 A block, A heads and the high nickel content makes it virtually indestructable. Then to have a well known Olds supplier tell me to change out the crank, rods and pistons to a 455 and tell me that doing so will increase HP sounds suspect to me. I have the block being bored out to .030 over because the clown I bought it off of loved using ether to start it. Now a little shot of ether won't hurt but when you saturate the carb wth did he think would happen. #5 blew and scored the wall. When this 425 is done, with everything being done to it, I'm confident it will give the 455 something to think about. IMHO.

edzolz

IMHO the 425 is superior to the 455. Putting the 455 crank and rods in a 425 block makes it a 455. The only issue you will have with the 65 block is the 45 deg lifter angle and that is not really a problem. The larger lifters allow better cam ramping. The only pistons you will find will be cast unless you get lucky and find an older parts house that has some forged ones on the shelf, but cast ones are very good if you don't spray it. The shorter stroke and longer rod length make the 425 an excellent choice for a street engine.

Oldsmaniac

I prefer the 425 as well, the 455 has 30 more cubes and with that prob would put out a few more horses but I like the 425 forged crank and shorter stroke. I had a 66 Delta and a 68 Delta with 455. Both were HC engines and in my case the 425 had much more snappiness and response to the pedal. The only 425's that had the large lifters were those in the Toronado 66 and 67.

40 Olds

I have ordered 425 flat top pistons w/valve relief from the well known supplier. these should give an increase in comp, not much but some, along with the edel alum heads,cam,intake, rollers, carb, headers it should breathe like a mother and from what i've read they love to breathe. Just got the 400 trans back from the shop, valve work, shift kit, completely rebuilt and a new Hughes converter rated at 2500 stall, didn't go crazy with the cam do to streetability and wanting to run 93 octane

MDchanic

And, not to be overly picky, but the "high nickel" myth has been debunked on these pages.

Sorry, but it just ain't so.

- Eric

40 Olds

Sorry Eric, after consulting with a higher authority, it is so.

aliensatemybuick

God told you this? Then he must have read that on the internets too.

40 Olds

Nooooooo, actually the higher authority is my father, he actually mixed the ores that were used to make the blocks amoung other things. After working for the company for 35 + years I guess he knows what he was talking about.

MDchanic

Please present your higher authority. Chapter and verse citations would be helpful.
Though we respect all beliefs here, in technical discussions we rely on science.

Samples of various blocks have been tested by members here on the spectrometer. Consult mfgusa and wmachine for their work on this.

Two threads are here and here.

- Eric

edit: simultaneous post.
I think it would be educational for all to get the metallurgists on this board in touch with your father.
This would allow the beginning (ore mixing) and the end (content testing) to come together and arrive at a final, conclusive, and amicable conclusion on this subject.

oldcutlass

I always thought the higher authority was Al Gore, the guy who invented the internet! I hope we aren't going to argue this point again! The strength in the older olds motors was in the rotating assy's. I also prefer the larger lifter's.