The V8 Owners Forum -

Hi all.

See when the "internet" says about 0.0010 per inch for main bearing clearance.

Are the crank under-size sizes to choose on the likes of Summit racing equipment on top of standard clearance?

As with a 3" journal I'd be looking for 0.0030 clearance but the only options I can find are 0.002 and under then 0.009 and over.

I know the standard stock clearance is about 0.002. So if I chose 0.001 on a site I'd have 0.003?

I imagine I could be sounding very stupid but I just can't work it out.

Thanks all

Marty D

3" journal ? That must be one massive engine !

Pontiac 455 has 3,25" mains and Pontiac 400 has 3" mains.

If you choose the correct bearings for the crank size you should be close.