Its almost that time, ive been saving for awhile now and im ready for a 350.

The plan was to get an LT1, but ive heard mixed reviews about the Opti-spark issues and i know the A/C is an issue. And I dont know if its worth the "hell and high water" to do the wiring and fuel/power steering lines. So lately ive been reading up on the L98. And the only issue is the lack of a computer, but that doesn't really bother me.

And the L98 swap seems more affordable and more of a first swap. and a pretty tourquey motor.

Ive read almost all the swap guides on this site but none really do a comparison of the two, So the professional opinions would be cool.\\

 

L98:
Basically as close to a bolt-in as you can get. Full swap take-outs are available, or you can piece together your own. ECM and harness are fairly easy to come by (you can use LB9 parts if it comes down to that). You will need to drop the tank and install a TPI fuel pump. But, no fabrication or aftermarket swap parts are needed.

A good seat-of-the-pants system, but real power upgrades can get expensive and will be limited vs. LT1.

LT1:
The Opti issues are way overblown. Improvements were made, but problems are easy to avoid. There is more wiring to do - swap harnesses are available, but somewhat pricey, and not really necessary. Keeping AC gets a little more involved because the f-body LT1 compressor placement interferes with the 3rd gen K-member.

Benefits are much better power without sacrificing driveability or economy. All of the negatives are up-front (higher cost, effort vs. L98).

Transmission:
You didn't say what you planned there, but a T5 will be life-limited behind either one. You can keep it alive, but don't plan on beating on it.

 

thanks alot man, that helps alot.

im going with the T56 6 speed, i have a T5 now, but its seen better days. So its going to have to go.

but thanks again for the in-depth responce, ill post an update and let you know what i come across

 

Do a carbed L98 if you want power and bang for the buck, a LT1 will not make more power with good heads and cam.

For economy and i guess some will say reliability, the TPI and LT1 is ok, but i have had nights at meets when i start my carbed 383 and it stays running and they LS1 guys stuff dies a couple of times before it runs. They say it is in the tune....blah blah.

 

Im definatly going fuel injection. Nothing against carbed cars, but i like the technology.
I think im going to go with the LT1, might be a little bit of work but worth it for sure

 

The LT1 isn't enough of an upgrade to worry about. A buddy of mine had a 94 LT1 automatic Z28, next to my 91 Formula L98/automatic, stock vs stock, I regularly put a car length on him from the start that he never recovered. Even after he did a few small mods he was still just even.

 

well there pretty much the same motor,
just a computer upgrade on the LT1

but the TPI has alot more tourque

 

Not hardly. Different intake port arrangement, different combustion chamber. Much better flow and combustion efficiency. To say nothing of the reverse flow cooling system.

Try again. Peak torque was the same.

 

Try again. Peak torque was the same.[/quote]

really? that suprises me, i thought the lt1 made 300 wheel tourque, and L98 made 330? Guess i was wrong.

 

Don't waste your time w/stock figures. Torque along w/calculated horsepower can be moved anywhere you want it to be in the RPM with the right cam, heads and intake. Lets say that theoretically you were right about the L98 making more torque than the LT1, all the LT1 would need is the right camshaft and it would immediately pick up (what you consider it to be lacking) power down low. IMO, stick with an L98, as it is a much easier swap in general, and there are an abundance of better breathing intakes for it out there to choose from, including the LT1 intake swap if you so desire....

 

Peak torque is only part of the story, the lt1 didnt makle peak until 4k, the l98 did it at 3200. If you compared their actual power bands, the lt1 would come on later and eventually stronger, the tpi would start strong and die out sooner.

I think it's perfectly safe to say the l98 is a torquier motor than an lt1, factory at least.

edit: the numbers i see show the l98 peak as 330-345, the lt1 at 325-335 over the years.

 

thats very true. plus im not too worried about the figures anyway. They definatly matter, but i just need a street motor(daily driver) because it going to see some highway miles(200 mile trip to Chicago), and a couple of passes at the strip.

Ive seen that intake swap done before, is it a direct fit, or does the throttle cable need a little fabrication?

 

I went lt1 and all in all it is worth it. the stock l98 is not a revving motor its for low down torque and does very well at it. The lt1 is just a shorter intake runner design that will rev higher and and make more peak hp with the same torque numbers at just a little bit higher revs. If you ever want alot of hp out of the l98 you change the intake to a shorter runner design so you might as well start out without a bottleneck.

4th gens are heavier than our thirdgens so if you put a stock lt1 in a third and the stock l98 in the third and race i almost promise that the lt1 will win every time. Ive done it. Although im not completely stock but neither was the other guy

The swap isnt that hard. Im 18 and i figured mine out in 2 months start to finish. If i can do it.. So can you. I might add i think i did a very professional job at it.

 

congrats man, not many people can say that. Im 19, and pretty much all on my own also. How was the wiring and fuel/powersteering lines swap?

 

The wiring IIRC is about 8 -10 wires not bad at all if you have a understanding of wiring. The fuel lines you can make or buy them get the fittings and some FI rated rubber hose the PS line was easy just a little trial and bending.

 

yeah thats what i figured, all you hear about is nightmare stories about the wiring, and people charge an arm and leg to do it. Someone told me close to a grand to have it professionally installed

what fuel pump do you think? i was thinking Walbro, but they had that big recall and it has me a little weary. But ive heard a few people tell me the ebay fuel pump works great. I dont know about that. I was thinking maybe a Holly255.

Thanks again for the advice guys, its really helping alot

 

i had jimsperformance do the wiring he grafted them both together for around 700$ it was worth it but if you dont have the money i was very close to figuring it out using the lt1 wiring for dummies thread, i could probably do it myself now but only because ive been at wyotech learning about wiring. I was under a time crunch because it was my only transportation at the time.

 

yeah wiring is really nothing to mess with. But i read that thread about LT1 wiring and it doesnt look too bad.
I guess well see how that works out.