First of all I'll tell you I have an 88 IROC with the L98. Do these have the 083 heads? I have been reading tons of posts the last couple of nights about cylinder heads. While I wasn't going to touch the engine this winter I have been thinking about the heads.

Most people here will say its not worth it to bother with the stock heads but I did find a couple of guys here who have done some porting and came out with decent flow #'s.

I already have an intake on the car (Accel lower, AS&M runners) and would definately change the cam if the heads were going to pulled. Probably something like a Comp xr279.

I can run consistent 13.80's as it stands now but would like to dip into the 12's with a new combo. Think it can be done on the stock ported heads or not?

Bob

 

If your engine is stock you should have the 083 heads. All F-bodies w/L98's came with them.

Course I ordered a reman. engine and it came with crap caprice 350 TBI heads. Ugh....nasty. Found out later they dropped my compression big time.

 

its a hard call. I have been debating on the same thing. They do get good flow #'s with bigger valves and a good port job. Depends on if you are going to do the porting yourseld or have someone else do it.

 

Talk too F-BIRD'88, he has alot of porting exp, his 081 ported heads flow nice. Him and his friend do porting, If I remember correctly his $'s were not that bad either.

 

If you're going to port them yourself, sure, it's relatively easy to get some good improvements on the heads. But if you replace the cam you'll need new springs and such as well, where as with new aftermarket heads they'll come with springs that can handle most moderate cams. Check out my posts, i broke down the comparative costs a bit.

Short answer is if your building a mild engine the porting the heads can get good results for low bucks if you do it yourself, if you're thinking about going for a wilder combo, the cost effectiveness quickly goes the other way.

 

I wan't thinking about anything too wild. Stock bottom end. Just want to put in a new cam and have the heads worked a little.

The goal is to get into the 12's with this combo.

Bob

 

Wow those are awsome numbers out of an L98 with only full exhaust, is it stock besides the exhaust?

 

Yeah, Im with you... high 13's on exhaust!!! Talk about your factory freak!! Take that 5.0 guys!!!
did you get a set of 113 heads for free? hehehe.

 

double post

 

Those are normal numbers from a typically modded L98 car.

It shouldn't be too difficult to get 12s in the qtr out of ported 083 heads, the right cam and converter.

 

maybe with other mods.. but to drop .5 sec or more? I figure that l98 cars ran 14.3-14.5 in the 1/4... now its running 13.7's? I wish I could drop .5 or more after exhaust... I put on the hooker cat back and with a ported plenum and still am running 15.3 in my 305, same as I ran stock.

 

I have to agree, this is not your everyday L98, ur one lucky guy, have fun with it.

 

Did you read his post?

Plus his sig showing free mods, headers and exhaust. Basically the same mods as my car. I think I'm going faster than him. Yeah, a freak car...he probably should be running a couple tenths faster than me...since my car is old...and has a tight converter, and my 60 foots are relatively slow for my times. Again, these are typical times of similarly modded L98 cars that come with the 3.23+ posi-gears.

Edited to prevent a flame war.

 

ahhh yes... didnt see the base/runner combo.. Just looked at his sig. In that case, thats a very good time. Im tired of hearing people saying that TPI takes a lot to go fast... an almost mid 13 run is pretty dang good for "80's technology"

 

Hm, my Iroc is capable of 14.3 right now. I can't do it tho, cause it's all in the 60'. However, I have a close to stock car. Look at my sig. Some headers, a catback, and the nitto555R's I am going to get put me right into the high 13's! Whats so wierd about that?
Anyway, just noticing that everyone seemed so impressed, and I havent thought twice about high 13's. In fact, I am pretty sure I can get a 13.9 with just adding a ported plenum, prom burn, and the nitto555R drag radials.

 

You should be able to do it with the converter and DR's. Its agreed that with a crappy 60 ft on htese cars the et really sucks.

I actually dipped in the 13's a few years ago when the only mods it had was the exhaust. Didn't really pick up alot of et with the intake.

I am now also running et streets but with the stock converter. I can only get 1.95's. Probably with a better converter I could get a couple of tenths too.

Still has the stock 3.27 gears in it too.

Bob

 

well, i was impressed since the only mod he did was exhaust... and he cut .5 off his time. Prom burning, Nitto's and other work would have changed my mind. If after prom tuning, all intake work, full exhaust, and traction to get 60's below 2.0, 13's is not bad... but for a stock car with just some messing around and full exhaust to hit 13.7's is pretty good to cut .5 or more off his time. I have had zero gain from any of the mods I have done... I just keep on hittint 15.3's. Cant seem to get any better.

 

What times are others running with the stock "peanut" cam? Is a 15.3 a good time for that cam? Is your posi working? What gear ratio? Have you done a complete tune up...such as fuel filter, checked fuel pressure, AFPR, cleaned injectors, timing, etc? just asking

I would think with the zz4 cam your planning, and some head work doing a quick bowl blend of the intake and exhaust and a little work on the short side radius as well would make your day. Plus better gears and a working posi if you don't already have that.
Take it for what its worth...

 

dont have any times of other people but seems to be just marginaly better.
posi is fine
2.73... yeah they suck, but its what I got.
Yes, fuel filter, plugs, MSD wires with MSD coil, timing is good(set at 8*). I havent checked my FP and I dont have an AFPR, but I plan on changing that soon.

 

Back when I had the stock TPI with just a ported plenum, AFPR, Lunati 216/220 cam, Torquer SR heads & E-brock headers, 3" exhaust w/cat, it would run 13.6-8 all day. I would not doubt his combo (well tuned) can run those times.

 

Just to clear this up, i wasn't doubting his times, i was just commenting they were good. I don't think i should be critized for complementing someone. His sig says 13.79 with exhaust and free mods, so i would assume he ran that w/o base and runners. Also i'm not saying high 13s are awsome, just very good for a L98 with exhaust.

Not trying to start something, just showing what i was thinking.
JP

 

basicly what i was thinking too.

 

I do agree that it does run good for what I have done to it. Even before the intake it would run 14.0's.

I've seen other L98 cars struggle to get high 14's at the same track.
Remember though to run a good # you gotta hook. That's why I bought the ET Streets.

Bob

 

Check my sig

It's not 102mph though.
Great power!

 

that is some great 60ft!!!

 

Thanks,
The 3.73s helped alot on that. I was running 13.8-14.0 with stock rear (3.23) and pulling 1.95-2.0 60s.
Charlie