BigBadGTA

How much power would a set of SLP runners, headers, and a catback make on a stock L98? Thanks! I was gonna ask for recommendations on headers too. I need them to have air tubes so I can pass Nevada smog please, and not too expensive. Thanks guys!

Tony89GTA

iTrader: (7)

You will probably knock off 3 to 4 tenths on your times.

Artisan

I had a 305 and made 226/290 at the rear wheels.

Edelbrock TES
3 inch under the car/ Loudmouth muffler/ no Cats
Owner ported/simesed Plenum
Simesed SLP Runners
Simesed/Ported stock intake
adjustable regulator
1.6 Roller Tip rockers
underdrive pulley
de screened maf
gutted airbox/ K&N filters
160 Thermostat/cooling switches
Swapped T5 for T56
Tunning by TBI Chips

The straight shift is worth about 5% better rear wheel power then the stock automatic 700r. If you take the 350 in consideration its worth probably 15 - 20 rearwheel horse power if everything was the same. Are you looking to make more power later? If so you will need to look at which headers you use and what size exhaust system you go with.
You will need to siamese the plenum, and port match it to the runners. You need to open the slps up and knock the wall out/siamese them down to about an inch or so from the base. The base will need to be ported to match the runners and the heads. Preferably all the way through. There is a guy on here that does that too.
I would think you could get to the 250/260 area if you did everything I have done with larger engine and headers.
Dyno Don is supposed to meake some of the best headers on here.

VincentZ28

iTrader: (2)

1 3/4 SLP headers or Dyno Dons Headers(both are shorties headers) with a full exhaust system alone will make at least 248-255whp on a stock L98 G92.

BigBadGTA

Thanks for the reply's guys! What I want to do is beat up on my dads 05 Mustang GT. I think I am going to wait until I have money to rebuild the entire engine before I bother with anything like heads or a cam. The car has 87K miles on it and runs really strong stock. I really want to just get some shorty headers without air tubes, and remove the cat completely but I cannot just yet. How hard will it be to install headers on my car? My car is pretty much rust free but I don't think the manifolds have ever been off the car since new. How often do bolts holding those on break off? My car also has A/C on it, so will that make it hard?