I am sitting on some money i would like to dump into the vette.

working with an '91 L98 I have just rebuilt from the block up - essentially stock (125lb springs in the heads, milled, and 3way valve job) - and I have already replaced these items.

Injectors
Fuel pressure regulator
Exhaust(magnaflow, new cat)
Fuel pump
Dewitts radiator and SPAL fans
assundrious parts and modules.

What would you do. I am trying to decide whether or not to buy a crated LT1 - buy a used LT1 and build it - buy a used L98 and make a 383 out of it - make modifications to my existing L98 that obviously has some legs in it left after the rebuild. I am still sitting on the block, pistons, cam, crank that came with it - and they have 130k miles on them, but the walls werent scored, and seems strong as bull.

I just want to make sure i head in the right direction. Can i get enough of a performane increase by replacing the intake with SuperRam or something similar, chipping it, and putting headers on it?

Am i throwing good money after bad, and should swith out to an LT1, LT4 or something else ( i have seen ZZ4, but i dont know what that is )

Opinions appreciated!

 

Anyone care to comment?

 

The problem with the LT1 would be that for all the work involved with changing it over it might not be powerful enough to warrant all the work. If it was me and I am a racer, I would buy a 400 inch block to use. With this block you can make a 377, 410, or 434 inch engine to fit your application. These combinations range from high revs (377) to good power (410) to just brutal (434) and have the ability to really put out the HP and torque. If you run an aftermarket intake with these it would be very fast depending on the cylinder heads that you put on it. If you only have a few thou to put into the engine I would spend cash on cylinder heads and cam since that is were the power is made. If you give me a better idea of what you are looking at getting out of this engine I would be better able to give you advice and also put the budget into somewhat of a perspective so we don't get way out of league there. I would imagine that you want to spend as little as possible so adding parts to the short block that you have to get to say 450 hp would be a good start unless you are looking for something more that will need to stand up to some abuse once in a while. Let me know and I will chime in with a more specific combo that I would recommend.

 

Well, i am looking to keep it a daily driver, but i would like to make it as fast/reliable as possible. I know that is a delicate balance, but i want to smoke most everything on the road, but still be able to take a girl around in it.

Does that help?

 

Use the money to pay for GAS to drive it.....

 

/bump

 

It all depends on how much cash you have to spend. IMO, this is what I would do:

Longtube headers, hi-flo cats, and catback system
Modified LT1 intake from www.lt1intake.com
Computer tune from www.pcmforless.com

If you can do all that, and still have money left over, an LPE 219 cam or a copycat thereof would ge a good choice. Accompanied by a custom computer tune.

Still got cash left? Heads would be the next step if I were doing it. Professionally porting your stock heads can yield great results, or you can go to an aftermarket vendor. Trickflow makes a decent bang for the buck L98 head, as does canfield. Again, custom computer tune.

If that's still within the budget, a stroker is the next step. Scat makes a cast 3.75 stroke crank that will reliably support more than 500 RWHP. I'd probably go that route, and use some budget minded forged rods and pistons. I've had good luck with Probe rods and pistons in the past, so I'd probably use them again.

Design the whole thing with about a 10:1 compression ratio, and keep the cam on the reasonable side, and it should drive almost stock. Another custom computer tune, and there is no reason you shouldn't make 350+ RWHP. 400 RWHP isn't out of the question.

At this point, if there was still money left over, I would buy either a stall converter or a clutch, depending on trans type.

If I STILL had play money burning a hole in my pocket I'd probably install a nitrous kit. I should be able to make 500 RWHP/600 RWTQ on the bottle, and my girl friend could drive it to the store.

That's just one way to do it. You could supercharge the car, or build it another 100 ways. That's just what I would do if I had money to burn.

Always remember, people on the net will spend your money much more freely than they would their own, so take internet advice with a grain of salt.


I wouldn't consider swapping to an LT1. Lot's of work for only about a 30 RWHP gain.

 

If something in the 400chp range is your target you can just continue building up your L98 block:
-port & work the #113s or go with new heads
-a nice cam (zz9 or 219)
-FL headers with dual exhaust & dual cats
-Accel base & LT runners
-AFPR for tuning
-custom chip for fine tuning

To finish off the drive train do a shift kit and 2,000-2,200rpm tc. If you plan on really thrashing it at the strip install a D44 rear.

You should be able to run mid 12s even at a track like Firebird and be very streetable.

 

It is really nice in this type of build to start from a lot of inches. If you want to be fast on the highway you will run into some quick cars! I prefer to build the bottom end and run it while I save money for the ultra parts that I want. Cylinderheads, cam, and intake is where it's at but, that is also where the most cost are at as well. My advice would be to again, pick your HP number up front! Then put together a bottom end to take that abuse and them some. Then pick your parts for the top end and get what you need. If you are thrifty you will probably end up with some gas money for next spring. If you want to put out a HP number at rpms I can list some specs for one of my engines that is close enough for a parts comparison since if you want to be king of the hill you will need some serious stuff. Hope this helps.

 

Great info guys!

So what i hear is go ahead and stay with the L98, and just build her stronger. Now with a block that has 130k miles on it, would you all recommend i build another to take the punishment, or would 130k miles on the pistons, rings, and crank not worry you?

 

Well the pistons and rings should be replaced, the crank will be ok unless things get out of hand with tq and hp. Just tear it down and look at and see what kind of shape it's in and take into account what kind of power and life you want it to live.

 

So rebuild the L98, change the intake, ignition, add the headers (coated of course) and put variable fuel pressure on it to work with the changed intake.

Anything else?

 

/bump

 

Go Wild and Torquey.
383

 

How much money are you sitting on first off.....and do you really want to dump it into you car?

 

I am personally a fan of crate engines. You get a warrenty. Someone else figured out the cam, springs, lifters, pistons, heads, etc........

You can get a crate engine in about any hp you want that would still be drivable and have the torque band where you want it. Do you really want all your torque at 8000 rpms or do you want heavy torque at 1500 rpms and carry it thru to say 6000.

Crate may cost a little more in the long run but you know it will run and stay together or they will give you another one.

 

Knowing your budget would really help.

 

well - budget is in the 2-3k range

 

well - the budget would be 2-3k or so.

 

With that in mind I would freshen the bottom end up on the L98 and upgrade the connecting rods to a forged H beam (eagle is good for this app.) and then have the assembly balanced. Also have the block align honed, this will make sure the saddles are true. Then I would have a good 3 angle valve job done, throw in a good cam and upgrade the EFI with the rest of the money. These things get really expensive but with the crate engine you get a mass produced unit that is not really race ready as far as machine work goes. Get with a reputable engine shop that builds real race engines and spend the money on the machine work! You will have a much better unit when you are done. Don't step over dollars to pick up pennies because you can't win the race if you don't finish! Just my 2 cents though.