out of these two setups, which would net the most power and approx how much if you had to do a rough estimate...

1. VQ35 shortblock, port and polished VQ30 heads, 2000 VIM, JWT heavy duty valve springs, JWT cams, tuned and rev limit extended to 8K....(11.3:1 compression, 0.5L more displacement)

2. complete VQ35 longblock (pathfinder) with 2000VIM

both would have full bolt on mods and AFR fully dyno tuned...

also, when you swap in the VQ35 shortblock...would you keep the VQ35 crank POS? thereby allowing easy use of the emanage ultimate in extending the rev limiter and advancing timing (since only the vq30 crank pos signals are having the problems being deciphered by the emanage ultimate)? or would it only be kept with the complete vq35 swap

 

I have no idea what the JWT cams are worth, I haven't been following all motor closely enough in the last couple years, but a 1 point increase in compression results in about 4% power gain as a general rule of thumb. However someone else will be more qualified to answer the rest of your question. I do know that VQ35 heads flow supposedly significantly better than VQ30 heads do. You say you are porting them but who's doing the porting on them? Do they have a flowbench? The problem is you can't just start hacking away at them and be assured of gains. You can port heads but if you don't port them properly you can gain zero power, or even lose power.

Given the cost of option #1 and the uncertainties I'd be goin with option #2 personally unless you know the person porting the heads is going to do a good job, and you know that the JWT cams are worth the trouble.

 

they do have a flowbench and they have been port and polishing for years upon years....but nonetheless, I do know the VQ35 heads flow better...but I kinda like the idea of having higher compression from the VQ30 heads...plus the fact that I would not be letting the VTC's go to waste without swaping over the entire vq35 harness and ecu...and then the e-gas as well which in my book is much worse than cable type throttle which I have always found to have worse throttle response which is definitely much worse for autoX'ing and road coarse racing--primarily what I would be doing with it...

 

Use the superior heads. Just a VQ35 I/H/E setup even with our handicapped ECU's will yield ~230whp/230wtq.