Andrei, have you considered running e85?

I thought about just adding 20% more fuel and using e85.

There are other problems with that. I'd like to run everything on pump gas.

e85 is more than 20%... 48.7% by my count...

pure gasoline has a stoich AFR of 14.64:1, compared to the 9.846:1 that E85 is stoichiometric at.

Let'* take a step back and weigh options. I've said quite a few times that I considered a front Plog to be "poor man headers". The rear S2 manifold is very free flowing and any porting to it is minimal at best. If the stock S2 manifold would work for you, I'd seriously consider a 2.5" or 3" downpipe with that setup. The largest difference would be reasonably small. And unless you were to build a huge motor, it should be fine for a 3.4 setup.

Running perfectly is all relative. A car that is tuned in August runs great in the summer heat. A car that'* tuned any other time of the year runs good at that time. My suggestion would be to have a tune for each season if you plan on running all year. That and constant tuning is how you have a dialed in tune.

Gotta go back to see if you plan rockers. Once the front manifold restriction is gone (and U bend on W bodies) then the exhaust is relatively unrestricted. The biggest restriction at that point is flow through the heads. Either adding rockers or a cam helps, getting ported heads with larger valves really makes power. And heck.. cooler air from a Gen V or turbo would be nice long before heads.

Dan..that GP with 5 degrees either needed a tune or there was a mechanical issue.

I did Tune it Bill, he had to run low timing. He'* now cammed and a S2 intercooler and running a 3.1 pulley with about 16* timing. His engine just seems to not like timing.

i was running a 3.4 on my GP without headers or plog, and i was fine for a long time even sold it with that setup.. usually you shouldnt need headers for running a 3.4 on an L67 with a 3" DP you shouldnt face any problems, but as they mentioned before having NA bottom end could be alittle risky since you have a higher compression ratio to start with, so i would go with a 3.5 if you're cant fit the headers in

as for the 3.5 i might have one for sale left from my GP parts but only problem its MPS

My Bottom end isn't N/A, that'* Jon'* motor. My engine is a 2000 L67 from the bottom up.

Where do I get said powerlog? Is anyone selling one anywhere, or do I have to buy it from someone? Am I understanding it right that the front powerlog alone, with the rest of my planned modifications, would allow me to run the 3.4?

At this point I'd like to send the headers to Milzy Motorsports for a quote on what it would cost to have them modified, and then decide what to do from there. If its too expensive, I may just sell them and get a front powerlog, if everyone is saying that it would help significantly.

Oh and another thing, i have to pay someone to make me a 3" downpipe for a 1st gen w-body, since nobody makes them. My understanding is that it would cost me ~$150 to have someone make one. The problem here is that it would cost me another ~$150 to get a powerlog, and the rough estimate so far for modifying the headers is $250-$300.

ops, sorry my bad.. didnt pay attention

k so you have an L67? if i were you i wouldnt even bother with the headers or Plog for a 3.4
what i would do i would install the 3.4, tune and scan
Plog would help a bit but its not a must.. most guys on gpona dont touch their exhaust mani with a 3.4 pulley, if you're running a 3.4 just install an intake, 180 stat, 3" DP and colder spark plugs would help alot.. and tune according to that.. at the end every engine is different.. mod and SCAN always SCAN

and i also might have a plog for sale i have to look in my garage.. if i do ill let you know..

If you could please look quickly, I'd very much appreciate it. My time is sorta running out, lol.