springer_4

Will a set of Vortec heads Fit on the L98? They seem like good heads and I have a set just laying around..... More or less I'm trying to get just about 400HP without goin into a new converter, Let me know what the best setup would be, and yes I'm kinda on a budget.

mpilarZ281992

I believe the vortec heads will work; however, other members on the board are the expert. I dont think you have have much luck on heads alone for your 400HP goal, you will need to change your cam as well. Not only that, but unless you upgraded your intake and exhaust components you will have usless power. So what is your set-up at this time??

Gtpguy

They will fit, but you will need a specific Vortec Tpi base intake manifold. As the bolt pattern is different. And then you might as well get some aftermarket runners to match the flow.

400hp will be very tough while retaining TPI.

springer_4

Stock set-up, I already plan on new runners, headers, Hot-Cam and also bigger Throtle body, custom tune and I also figure sence the Vortec heads flow better might do alittle work on those also. Just wondering what power I might expect out of that setup. I figure I can do all this and do a self rebuild on the bottom end also to freshin that up too..... Wish me Luck it's gonna be a project. I've done LT1's and LS1's not it's time for a TPI, also I'm hoping 375-400 at the crank not the wheel"s.

rik89gta

You should seriously consider a Vortec HSR intake upgrade if you wanna make 400 at the crank. No sense in buying a TPI Vortec base and aftermarket long tube runners. It'll end up costing you more money and You'll make less power. Be careful if you do any port work on the Vortec heads. The factory castings flow excellent on the intake port side. It's the exhaust ports and the valve springs that need a little massaging if you plan on making good numbers.

AutoRoc

As mentioned. modding a tpi engine is never cheap. It is also hard to make good horsepower because it was meant to make bottom end torque. The cheapest power while using Vortec heads would be to bolt them on your block, install a Super Victor Vortec intake from Edelbrock, and top it off with a 750cfm carburator. The intake is $240, find a used carb for $150-250... or just pony up the cash for a Pro Systems custom built carb that will be built and tuned for the engine you're building. It might run you $600-700. Much cheaper than the EFI parts + tuning you would need for 400hp EFI engine.

As for a different converter.. An aftermarket torque converter is probably the best performance modification avaliable to an auto trans car. Not sure why you would want to retain the stock unit...TPI cars appreciate a 2600-2800rpm piece and a mild cam/short intake runner engine would work better with a 3000-3600rpm piece. Stock is lame.

Another route is to sell everything you no longer need and buy a RamJet 350 crate engine from General Motors Performance Parts or Scoggin Dickey Parts Center.. COmes wth a warranty, it's fully tuned with it's own EFI system. Makes 350hp. Drops right in, uses your exsisting fuel system. Cost is $5000 roughly and it should be trouble free for YEARS on end and would probably up the value of your car if you ever needed to sell it. If it's weak, put a 15lb bottle of nitrous in the trunk and spray a 100hp shot whenever you feel the need to beat the car next to you. I've thought about how trouble free and fun this would actually be.

Goodluck! It's nice to see another car get taken care of to be honest.

springer_4

Ok, car has 90k roughly totally stock. My plans are pull the motor and freshin the bottom end up, and the rest I have 3grand for the rest to try to get 400HP. Give me some idea's or list of what I need also already have a set of vortec heads that are going on it also. So let me know what would make the power......

mpilarZ281992

Hmmmm. I say AutoRoc has a good idea. The high flow runners alone are not cheap (though they look awesome). You may want to scrap the TPI if cost is an issue. With a HotCam you mentioned you will need to get custom tuned (that will cast up to $500 if dyno-tuned by someone). I kept my TPI for the low end torque and used a ZZ4 cam, but to all their own. I loved the look of my high flow runners, ect...; however, I swear I spent over $7000 by the time I was done. If I had to do it all over, I would prob. just buy a high performance crate engine. Good luck.

AutoRoc

PM sent. As stated above. It can be a very unrewarding hassle doing this, especially if it's a first time effort. Odds and ends also add up. Love the car, hate the powerplant.

sidenote... buy a 3" exhaust system with a single out, ANYTHING but the 80 series flowmaster muffler setup. Good sound is more important than those annoying slash cut exhaust tips burbling out the crap that is produced by the 80 series Flowmaster. thank you.

haha

Kevin91Z

My dad made around 315 RWHP and 380 RWTQ with a set of Vortec heads, ZZ9 camshaft, Scoggin Dickey Vortec TPI intake, SLP siamesed runners, Dyno Don 1 3/4" headers, etc. It went a best of 13.01 @ 103 MPH at 3000'+ density altitude.

Remember you will need a spring upgrade and a change to screw-in rocker studs if you use a cam with more lift than .470"

springer_4

Just picked up another TPI 350 from an 88 Iroc 89k on it, So I think I'm gonna rebuild that over the winter. I figure 3grand will get me some decent power, maybe not 400HP but close. In the meantime Bigger throttle body, headers and exhaust. Now all I gotta do is alot of reseach for the best way to reach my goals.

Gtpguy

Don't waste money on a Throttle body unless it's FREE. You don't need it right now.