Your new crank and main bores are within spec !
Pontiac set up there non RA / SD 3” main production motors for .0002” to .002” clearance, so your not far off from that .
If your main bore checks out dead on then I would not line hone it, but look for a bearing set to provide that extra .001” or so to get you to .003”.
If you can’t send back those bearings you have now and they have a break in coating ( which I have never found I need for) then I would wet sand it off from one bearing set with 800 grit paper and then drop them in one main saddle to see where your clearance move to.
Another possibility is if your line bore is only a hair out then just get a line hone job done with these bearings in the block.
This is in a way what Jenkins did with his SBC 400 motors when converting them over to run the smaller main 350 cid cranks.
__________________
Wernher Von Braun warned before his retirement from NASA back in 1972, that the next world war would be against the ETs!
And he was not talking about 1/8 or 1/4 mile ETs!
1) 1940s 100% silver 4 cup tea server set.
Two dry rotted 14 x 10 Micky Thompson slicks.
1) un-mailed in gift coupon from a 1972 box of corn flakes.
Two pairs of brown leather flip flops, never seen more then 2 mph.
Education is what your left with once you forget things!
Last edited by steve25; 08-05-2025 at 07:45 AM.
|