I pulled a big block from a 66 olds 98 and thought it was a 455, but I cant find that they put anything other than a 425 super rocket in them, any help would be appreciated!
brian

Hi drgrcr, hello everyone,

Welcome to TOC.


All big locks to '67 were either 400 or 425 inches. There were no 455s until '68.

Depending how you are using it, and/or who you talk to, the 425 is a better engine anyway.

All Olds V8s from '49 to '90 were rockets. What is a Super Rocket?

Regards, Norm

thank you, I thought I read that is was called a super rocket , do all the accesories fro a 455 bolt to a 425?, I am using it in a jet boat, not really making a racer out of it, just want to have a nice boat, I think it will bolt up where the 455 is now????

Yes. Except for the crankshaft and piston/rod combos, all Big Block Olds are identical.


That puts it in to the "depending on it's use" category. 455s lower power band makes it the better choice for use in most boating applications.


Lots of latitude in that statement. Tell use more about your boat and your planned use of it.


I assumed that. Lots of misinformation floating around. Some of it even gets to the internet. Sadly, not enough people correct it when they see it.

You have a 425. Other than the, '65 only, rocker arm configuration, they are all alike. Any name someone chooses to add to it, does not change anything.

Norm

it is just a 20 foot jet boat that has a rusted 455 in it now, I just want to have a nice little boat to go out on and have some beers with my buddies and make some noise sometimes, I dont have to have the fastest boat on the lake, just have fun.

another question, will a pontiac dist. work in the 425, they both spin backwards right? if not, I am looking for a budget HEI type dist. did any cars have a electronic ign. stock that will fit in the 425???

Oiling problems were my concern, you will not RPM high enough to have any.


No.


You are on an Olds board. Olds and Pontiac turn in the proper direction, Chev (and the other brand Xs) turn backward.


Use any dist from a '74 to '80 Olds V8. If you cannot find one in a yarde, you should be able to get a stock rebuilt from any parts supplier. Eliminate the "resistor" wire from the starter to the coil, make sure it has a low resistance carbon button under the in cap coil, and call it good.


HEI is a self contained, electronic ignition. It was part of the GM emissions systems starting in '74 here in CA, and '75 in the other 49 states. It's more than adequate for anything under 500 HP.

I got these numbers with, fundamentally, the same ignition you already have.

One other item of importance that would apply to a boat. I was reminded of it yesterday.


425 (and 330) cranks have a slightly different bolt pattern on their flanges. One hole is off, but by less than ⅛". You could have a problem bolting it to your pump.

We had the same problem bolting my 425 crank to the dyno pump. Solved it by slotting the one misaligned hole on a 455 stick flywheel.

Don't know how hard it would be to do, on your jet, or if it already has a provision for both.

Norm