port and polish!
 

depends on the car and the shop you do it at. As far as HP gains...not a whole lot. This is something you should only consider if you are tearing your motor apart anyway.

^^^ Stock heads will flow pretty good. I wouldn't port-n-polish unless I was changing out the cams.

I ported and polished heads for years (as an amateur with some training)- mainly old Alfa heads and, more recently, heads for MINI Coopers. When matched to a proper camshaft, I got a MINI NA engine up from 108 WHP to 128. The same cam usually gives about 10whp, so it was a significant gain. MINI heads have fairly restrictive exhaust ports from the factory, though, so it was not at all difficult to find some power hiding in the castings.

If it says anything, though, I have not done the same to my (supercharged) MINI. Not that it wouldn't result in some gains, but really I'd rather have the super-reliable car I have now, and not mess with success. I'd most likely have the same attitude with a new 370z in the garage.

Ive seen Supra guys rave about the VQ35 heads compared to the monster 2jz. Excellent flowing heads from the factory. Id mod other areas waaaay before touching the heads. I believe the 1k hp Z from SP's[?] is still using the stock heads if memory serves. Gears and full bolt-ons with tune would be the ticket imho for now. No need to P&P unless you are trying to build the fastest, fully built and blown VQ37 in the world.

I agree. I haven't heard the same about the 37 heads, but I had already assumed that Nissan was trying to get as much power out of the motor as they could realistically without changing the total design of the motor.

It makes sense. The heads on the LS1 were near perfect when the LS1 first came to be. I'm sure, just like the LS1, there will be better heads in the next year or two for the VQs, but you really won't need them if you're only making 500BHP.

The VQ heads are a work of art... Across the board, every auto enthusiast says the VQ heads are the best flowing heads of any motor out there. I'm not sure how the VQ37VHR heads compare to the DE or HR 3.5 heads, but I'm sure they are better if not equal to the others.

^^^ LOL! They sure as hell better not be worse!!!!

^^^lol I agree. I think its safe to assume that they wont be worse than the HR heads. Wouldnt be surprised if the HR and VQ37 heads are flowing pretty much close to each other if not the same. Sam @ GTM would be able to answer that.

When GM went from the LS1/LS6 era to the LS2/LS7 era, the LS6 heads flowed the same as the LS2 heads. Physically they're the same heads with different part numbers.

Port and polish is a scam