I spun bearings and had valve to piston contact and need to rebuild.

If a 355 and a 383 both had LE1 heads, and a mild to somewhat aggressive cam that would make good power but still be a nice daily driver (I know that a 383 can handle a bigger cam and still drive well so this might be different)... what would the differences be in terms of HP/TQ numbers, drive ability, seat of the pants feel, MPG, etc.?

I am also considering building a 355 w. nitrous for the same cost as the 383 but am not sure that I would really get to enjoy the nitrous enough on a mostly street vehicle. Thoughts?

 

To clarify, I have read several times that stock or lightly ported heads do not flow enough air for a 383.

Does this mean that it will cause it to run poorly (i.e. worse than a 355 with same supporting mods)?

Or does it just mean that there is still a lot of power left on the table, but the larger displacement will still produce more HP/TQ under the curve than the 355?

I hope that makes more sense as to what I am trying to get at.

 

383 will make more power earlier and although the heads are "too small" it won't cause you to make
less power than a 355. That doesn't make it a wise choice though.

I was playing with the dyno simulator and both setups make about the same peak HP,
the difference is a 20hp or so max gain around 4500rpm or so
(tapering off to 10hp towards 2000rpm and 7000rpm)

Spend your money on upgrading to at least LE2 heads instead and Bret will grind you a cam that meets your needs.
The improved components, larger valves and better porting are worth every penny.

 

If I was just spending money for fun, I would get the bigger H/C. But I need to rebuild anyway and it doesn't cost too much more to get a 383. Does that change your recommendation at all?

Reason I am going with LE1 Budget heads is that my heads need some work from valve to piston contact and I was quoted at about $400, so add $160 for bigger springs for a new cam and I am almost at the cost of the LE1 budget heads so I figured I would spend a little more and get heads that flowed a good bit better.

I dont know if this is true or not, but I was thinking that it might be cost less to upgrade to LE2 heads later because a lot of porting will have already been done with the LE1 Budget heads.