Found this post in a 300ZX forum and thought it was interesting...

"VGs are very much like L-series in that you can mix and match lots of parts. ALL North American VGs have the same stroke and they all have the same size bearing journals. I do not know about the VG20 found overseas. The VG30E block cannot be bored to use VG33 pistons, the cylinder walls are too thin. The magic formula to build a VG34 is this: Bore a VG33 block .060 over. Use *stock* 1995 Infiniti Q45 pistons, rings, and wrist pins. Use VG30ET rods with custom, larger I.D. small end bushings as the Q45 wrist pins are 1mm larger. You can use any SOHC VG crank (they are ALL cast), but there are differances in front snouts and related accessories so use one you've got all the parts for. Avoid any SOHC VG crank that's been run with a serpentine accesory belt as these tend to break off the crank snout! The above VG34 combination is the one used in the off road trucks. If I remember right this bottom end comes out to 10.5:1 compression, perfect for a street motor. Sly said a VG34 with "good" cams and stock heads will make 250hp on 93 octane in street-trim. With port work and the "right" cams and intake a VG34 can make 300hp on pump gas. Sly says that no matter what you do they won't make power over 6500rpm as the displacement is too big for the head design. The question I've never heard answered is what happens when you turbo a VG34? I don't know anyone that's done it so I don't know what the limit is. I'm guessing the crank will come apart first. I've been told by many that SOHC VG cranks are short lived when 350hp is exceeded. It is possible to use the forged DOHC crank in a SOHC block but it requires a custom flywheel and messing around with a few things to make it go together. It's relatively painless but I've only done one so far. If you are thinking about building any VG be warned that they are difficult and expensive just to rebuild stock. Many automotive machine shops cannot hold the tolerances neccesary to make a VG live, especially if it's warmed-over. Rebuild parts are also expensive, but then they should last 200k miles."

Zpeed7

You could trade in your Xterra and buy a 350Z... then you wouldn't be concerned with all this.

Post what site that came from. I want to hear more.

Onlyonedr: in your sig...just checking to make sure it's correct. the frontier v6 dyno's at 133 hp? 170 lb?
the torque is decent but the hp is unfortunetly what i expected .

That is on a chassis dyno (what the rear wheels actually put to the ground). It's a little more useful than the 170hp/200ft-lb that Nissan claims at the flywheel. Overall it's not too bad, about 22% drivetrain loss on the Hp number. That was a sweltering hot day in Houston, and I have Dunlop A/Ts on my truck which are over-sized and more aggressive.

Here's a link to the graphs of my dyno runs:
Dyno Curves

You'll notice the first two are lower than the third. I mishappenly left the A/C on for the first two, so now you know just how much A/C saps from the engine as well. Whenever I get to doing some engine mods I'll run her again, I did that for a baseline.

thanks alot. that graph was pretty interesting.
i have an xterra, but i figured the frontier and xterra have the same engine so there would be no difference.

Looks like you can see where the A/C compressor cycled off around 4400 RPM on the second run...

Brent

Pretty nice write up Zpeed7. Not ment as a flame, but it'd be cheaper to just sell the X, run out and find a used '01 Pathy with the 3.5. 250hp right out of the box. Hopefully when the time comes to sell my X I can find a 5spd 3.5 Pathy although in that case it might be easier just to do the engine build!

holy mother of GOD....

the a/c eats up THAT much power?!?!

(mental note: yank a/c system from X)

Yank it? Uh, just turn it off...