Hi gang it’s been a while, bought a new to me RV, retired and been traveling the last three years.
I am taking a core 68 455 to the machine shop tomorrow. Hot tanked, magnafluxed and bores measured. Mileage of this motor is unknown, I attempted to measure the cylinders with a dial bore gauge (thanks utube). From what I can tell 1.5-2 thousandths on them with barely a ridge at the top. But the shop will verify.
Here are a couple pics of the mains, do they look normal or “Abby” normal?

 

They look very good. What will the motor be used in?

 

You did ok there. That looks to be a forged 455 crank. You can get decent money for those if desired. Good luck in your build. Let me know if I can be of help.

 

Bearing look nice, maybe you will get away with a relatively cheap rebuild.
Steve

 

This is going in my 68 442

 

Hey Mark, just the guy I was hoping to chime in. A couple of questions, I know you aren't a fan of the Speed Pro Forged pistons, but I have a set of Standard L2323F's I was hoping to use these. Of course will have to wait for word from the machine shop on the bores. I was looking through this thread about PTW clearance. https://classicoldsmobile.com/forums...arance-132623/ Good info there. I also have a new cam (OE #406768 1970 442MT) I'm wondering if I'd be better served with a modern profile? just looking for a good strong street motor. That is a forged crank, I have a N crank I could use if someone needs that forged one!
68 442
Performer intake
C heads---or aluminum
stock manifolds
TH400 w shift kit and Breakaway Convertor
3:23 posi
Sparky built QJ

 

What set of heads would you go with for an inexpensive head rebuild?
Big valve C’s off a 71-72 Toro or small valve C’s from a 68 Delta

Poly locks? What’s a good one to use on these Comp Cams rockers? The lock nuts are used and I’d rather upgrade to short ones but still want stock valve covers.

Is .080 off the pads for comp cams guide plates? or just the thickness of the plates(.063)?

 

I’d do a TQ50 for your build (228(235@.050).
Crank choice is on you, N crank would be fine for your build.

 

Well I was wrong “Big valve C’s off a 71-72 Toro“ these are 69 C heads with big valves my buddy Kyle.

 

I am wanting to source new main bearings and found these... looks to be the same photo. Federal-Mogul and Sealed Power the same outfit??

 

Yes.

 

Same bearings here also.

Main Bearing Set 108M: Advance Auto Parts

 

Since that thread you posted was mine i will chime in.I am not making any recommendations on ptw clearances but i can tell you with the clearances i posted in that thread i just finished my third summer of beating on that motor and still no issues.I did have the motor apart for a rear main seal issue and seen no signs of damage from excessive ptw clearance. "Those pistons" are working out well for me in a street motor ,of course there are better choices but it came down to budget for me .The speed pros get a bad rap because of their older design but imo they are a good solid piston.

 

The bearing pics are all the upper halves, that can’t tell you very much. The lower halves , especially #4 is what you need to look at.


you don’t need to cut the rocker pad surface to use those guide plates

 

I know this is an old thread but after reading the comments on the piston clearance I gotta say, wow….lots of bs in there.

SpeedPro/TRW has changed that piston design over the years. The material they use now is VMS-75 which contains 11% silicon

its forged, but neither 2618 or 4032 spec, it’s their own proprietary aluminum. The piston has a slotted oil groove design and is now coated . They do spec a very tight clearance, like the latest ones call for .001” at the bottom of the skirt…I have a box here that’s older and it calls for .0015, uncoated.

having said all that if I’m forced to use these, like the customer already made the mistake and purchased them, I always add .0015 to .002 to the bore…remember, they say that’s the minimum

if it’s a + .030” 455, the final bore will be 4.157”

I’ve also cut them for locks to float the pins