[Aaronz28]

i found a 421 crank that was machined for a 389 mains. the thrust needed work so it was welded and machined to the 389 size. rods had to be machined to 40 under but still looked great.

using the eagle rods, and stock bore 428 pistons is there any reason this will not work, or is there anything i need to take caution with?

The block bored nicely to the 428 piston size so that was fine...

i just want to be sure that there is nothing i'm not forgetting here?

also, anyone know what the correct torque is for the cap screws on the eagle h beam rods?

Thanks

[chiphead]

I responded to your crank question before I saw this......

If using 6.625" rods, stock 428 pistons, and a 421 crank, it might just be crazy enough to work! Just do the math, and make sure your deck height is about right with that setup. Have it zero-decked to really make it run nice.
Pay extra special attention to the quality of the thrust main work. Improperly polished thrust surfaces will eat the thrust main inserts. Shoot for .005-.010" crank endplay. Are there any rear main seal issues to be dealt with? Check diameters and widths of rear seal surfaces of your crank vs a stock 389/400 crank. You may have to clearance the block to clear the larger counterweights. Be prepared to test-fit the hell out of this combo to prevent nasty suprises!

Good luck

robertg

[Bill Eveland]

I was going to do the same thing almost to my 389. I was going to use a 428 crank and standard bore 428 pistons . I still have the pistons to use, but the crank was junk. It should work,(if i'm wrong, Iv'e been corrected before) there may be a few small spots the block will have to be clearanced for the crank throws. I went ahead and bored mine to 4.120" anyway and used 400 pistons instead.

[PONTIAC DUDE]

I also make a main bearing conversion kit so that you don't have to have the large journal crank thrust surfaces welded.
Just cut the main and seal area to 389/400 Pontiac size.