For quite a while now I have been debating on selling my TFS-30400007 cylinder heads. I have been offered some cash for them, but not what I expected for a set of NEW heads. But oh well! My heads, and my NEW accel base have been sitting in my garage for over a year now collecting dust.

I have posted topics relating to this on other forums, but I get the same answers being that no one realy dyno's there cars, or 1/4 mile's them etc....I was told to make a post on here due to that this is a genuine hardcore L-98 website. I have been surfing on here for a bit now, but havent made too many posts.

This get me to this. I want to mod my 88 L-98. Right not it was alum 113 cylinder heads which I am gladly sell after I do the motor. I am 90% sure I am going to do the motor, but nothing is 100%. My gear ratio is 3.07's, and its a 4+3 car, So I am thinking the SR is the way to go. I originally wanted to go with the TPIS runners/ported plenuem/accel base, but from the researching I pulled up, the intake just wont rev to 5500, and make power there. So this is why I thought the shorter runner SR was again the intake to go with. I have a chance to buy a SR with the runners ported that I hope will be a good match for my heads that flow 260cfm@.550lift. Again they are new, so they have the 2.02/1.60 valves, and the springs are 1.46 duals, good for .600 lift. The heads are 195cc/62c, and the stock heads are 58cc, so this is another little problem. Do I mill the heads, or put a thinner gasket on, or just loose a little compression which is 9.5/1 stock.

Now to the cam. Which is where I am totally stumped. Everyone and there Grandma seems to go with the LPE/Accel 219 .525/.525 219/219. Does anyone else recommend a different cam. This 219 seems to be decent power, but it does seem a little wimpy, or is it the ULTIMATE L98 cam?

My car weighs around 3480 with me in it. The rear end is a D44 so its solid. My performance goals are to run mid 12's@111-113, and dyno in the 330rwhp range, and in the 375-380 rwtq range. The stock L-98 has 75000 miles on it right now, and runs 13.70@101 with a 1.95 60 foot.

I would LOVE to hear everyone's suggestions to what they did, and what 1/4 mile, and dyno #'s they got. If there is anything I missed, then ask away. I am still up in the air on what intake to use, but I am leaning towards the SR, and I have a chance to buy one for around $675. I havent seen many results with heads that flow 260cfm or so with a cam, and a TPI. I hope you guys can help a fellow L-98 guy out. This will be on the stock 350 shortblock. I have posted a thread along the same lines as this before, but I didny quite get the feedback I was looking for. Worth another shot! Dyno graphs would be cool!

Thanks alot!!

 

I am running slightly-modified Trick Flow heads on a 355 with about 10.5:1 compression, the LT4 HOT cam (218/228 duration and .525" lift with 1.6 rockers), and (until yesterday) a ported Edelbrock manifold and ported SLP runners. I made 290 rwhp and 346 rwtq with this combination, ran a 12.47 at 110.3 mph, and drive it every day (except in the snow). Everything about my engine and car is at:

IROC

Personally, I don't think the LPE 219 cam is the ultimate cam for TPI engines, as I've seen others make great power with the LT4 HOT cam. Mike Davis made 342 rwhp from a 350 with AFR heads and the HSR intake. The CompCams XFI line of cams seems pretty good too.

Everyone has an opinion on the TPI, SR, HSR, and Mini-Ram intakes. Since you have a Vette, the HSR won't fit under the hood unless you get custom-made plenum or a taller hood. You can make decent power with the TPI-style intake (SLP or AS&M siamesed runners) as well as the SR.

 

One thing that I always say to myself before building another is "Am I really ever going to race or dyno this engine?"

If the answer is yes then I will build a engine meant to go fast, if it is no, then I build more of a mild torque engine.

If you honestly believe that you will dyno or race that vette alot or often then build an engine for it, if not, spend your money on something else.

That being said, if you want an engine that is pretty fast go with the HSR or miniram. If you want a mild torque engine, go with a tpi or it's cousin the super ram. TPI's can be fast, but a miniram/LT1/HSR will ususally run faster if built with that intake in mind.

 

What do u mean until yesterday? 290rwhp isnt bad actually for a long tube setup, but I am suprised your tq wasnt a little bit higher. My car made 345rwtq with just exhaust mods. Thanks for replying.
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Thanks for your opinion. I am leaning towards the SR intake however.

 

I just installed a HSR intake, started on Monday, finished yesterday. These dyno numbers are with an automatic, so the numbers are lower than they'd be behind a manual tranny. I expect the hp to increase around 30-40 rwhp, not sure if the torque will increase or not.

 

Right on Greg. Actually I would expect around a 30rwhp gain with a SR, So maybe 40rwhp or so with the HSR. Goodluck!

 

The combination of 350, superram, 219 cam, and trickflow heads will get your goal in your vette. I have ran this exact combination in my vette, and then my Firebird, and in each car it ran the numbers you are after. The vette ran (on good air) 11.81 at 114MPH with RWHP numbers of 342 and RWTQ of 382. The Firebird with the same engine ran 12.49 at 110 with a six speed and it made 337 RWHP and 382 RWTQ. The power differeneces on between the two cars can be attritrubted to the better full length headers and better air intake path on the vette. The vette with the auto, less weight, and high stall convertor 60ft'ed much better then the Firebird so that why it runs 1/2 second faster.

As far as the head gasket goes I would run the Felpro 1094 .015 coated steel shim gasket to boost your compression. I am using this gasket on my 355 in my sig and I did use it in my 355 with Trickflow heads with goood results.

I did change the cam from the 219 to the ZZ-409 in my 355 just because I had it laying around from a prevoius build and I was interested to see if it would add any power. The end result was I picked up 9 RWHP and a little more power under the curve over the 219 but if you already own the 219 I would not sell it to buy the ZZ-409.

 

now thats good info!