I'm about to start building a L98. I have mostly stock parts, and I want the vehicle to maintain a stock look. What would be the best place to start looking for power? All I'd like is 300hp, maybe a little more, if i want to be greedy. Any suggestions?

 

It seems the cam and intake base would be some good areas to improve. I will be watching this thread as I am going to be building a similar engine next year. However, I'd like to go with aluminum heads for the reduced weight.

You could also go with a 383, which would look stock externally. I've built a mild TPI 383 before and it was a blast on the street...

 

Well, one of my options is rebuilding the motor with a LT4 hotcam, and port and polishing the stock intake and plenum, and maybe installing some shorty headers and a nice exhaust and a good tune.

 

with the LT4 cam.do you have to replace valve springs?....sorry to barge in on your post

 

I think you do.

 

That should get you pretty close. My 90K mi L98 with just exhaust makes 220rwhp, so I'm think a fresh 355 with LT4 cam and everything ported would probably hit ~250rwhp or so...

 

My L98 is making 272 hp with a stock cam and stock manifolds and stock cats. I just ported the intake, tuned it and added ZZ4 heads (which do not flow very much more than stock heads).

So with that experience:
Long Tubes x-pipe and duals
Tune
Ported Intake or new runners
1.6 rockers (to crutch your cam)
AFPR

Should bring you close.

 

272 at the crank? Or at the rear wheels?

 

Mine ran 234 at the wheels with headers and full exhaust. The hotcam is old, but it's still a nice cam. Won't get you all the hidden power that the new grinds can with their improved ramps, but I've known several satisfied Hotcam owners. You'll wanna switch to a double roller chain, and do some port work to the tpi. Maybe larger runners to match the porting of the intake and plenum. And as far as heads go, I would save money and buy some decent aft mkt heads rather than working the stock heads. The engine could still look very stock with a set of alum heads, once all the emissions lines and coolant hoses are in place you prolly wont be able to see them anyway!

 

234 at the wheels with just headers and exhaust...not bad.

 

Myself and another L98 owner here both picked up about 20rwhp when we went with hedman 1-5/8" shorties with y-pipe

 

GOTTA be crank. ...even then I gotta wonder. LOVE to see it be true, but that's pretty insane

 

272 Crank according to an iPhone. ABUBACA U should come check it out if your not a believer haha, seems like there are no thirdgens out here in eastern NC

 

How in the world can an iPhone hook up to engine & measure horsepower at the crank?

That was a rhetorical question, because I already know the answer...NOT POSSIBLE!

Lemme guess....Your basing that on some kinda simulation software, like Desktop Dyno? Or some kind of GPS phone-based software(which would be rear wheel hp)?

 

Its the exact same concept as a G-TECH, it uses the accelerometers in the phone and measures the 1/4 mile. Its pretty accurate actually, at least thats what hotrod magazine said about G-TECH and the whole accelerometer thing.

It called my stock GTI 197 hp when its advertised at 200.

But maybe you still dont believe me, maybe you will believe the guys at autoblog http://www.autoblog.com/2008/07/29/d...ormance-meter/

Or Road and Track http://www.bunsentech.com/2009/dynol...oad-and-track/