How much rwhp & rwtq would there be between the two motors( 4.00" vs 4.03" bores ) with ported 6.0L heads, 229/237/117 cam, and full bolt ons? This setup will also be used in a FI application so I would think the thicker cylinder walls of the 402 would be better. TIA

 

408-409 would be just as strong.

You are talking a .03-.035 overbore on a 4.1 spaced motor. I would personally go with the 4.035 bore 4.00 inch stroke motor. (409ci)

Lots of room for overbores/hones and you can be sure everything is where you want it to be with bore roundness and spacing.

Cheers,
Chris

 

You're talking a few hp/torque at a few points on the curve, very little at the peaks.

 

I'd say 4-5 hp diff !

 

I'de give it 2-3 rwhp. Usually there isn't much affect of boring an engine from what I've seen.(well at least not .030 or so)

Josh S.