well i just wanted to start this post to see what peoples opinions would be on this. so heres what im thinking i have a 88 firebird formula 350 and well the motor is pretty much screwed up. for starters the camshaft is bad because some of the lobes have some how been ground done so a.) the rest of my valvetrain is screwed up because of this and would need to be replaced b.) there are now lil bits of metal shavings in my engine too. so it would need a complete rebuild. also the computer is either screwed up or someone mess with it and now it dumps way to much fuel into my motor especially in the cylinders that are effected by this cam thing, and because its running rough it wants to fix the issue by dumping more fuel. and i have a friend that has 95 lt1 that needs some work well first of he got the car earlier this year from a guy as a parts car, the guy didn't know anything about the cars motor other than it had a knock of some sort. and well beside not really knowing anything about the motor its also missing a few things such as intake manifold, water pump and i believe fuel rails, otherwise i think that the wiring harness is there along with the computer. so tell me what you think guys build up L98 (that i already have) or a 95 LT1 out of a z28

 

instead of buying motors with problems, check the classified boards here. There is one guy who is selling his 406 for around 2800. And there are several other people selling to

 

Junkyards sell LT-1 engines pretty cheap anymore...they are a good fit in our cars, but require a special wiring harness....rebuilding the L98 will be simpler, but it won't perform as well stock.

 

LT1's can be had cheap. And performance wise its like a bolt-on L98 in most cases. The PCM's are usually easier to tune as well.

I say junkyard it.

Or go with a 5.3L Gen3 swap.

 

Personally, I'd stay away from any LT1 engine. I am not saying their terrible, but honestly, the production run wasn't that long for a reason. I mean, there wasn't an LT2, or LT3, like the LS series (discounting the LT4), and AFAIK, they lasted from 92-97, so obviously there was a reason for this. As a company, you don't invest the kind of cash it takes for R&D on an engine only to run it for 5 years.

Personally, if its a choice between the L98 and LT1, I'd be about the L98. If you're looking for a bone stock replacement for yours, its going to be slower than a stock LT1, but 300hp out of an L98 with proper mods (runners, intake, injectors, etc) isn't out of the range of possibility.

Just my $.02.

 

Agreed with posters above. L98's and LT1's that run well can be had for cheaper than rebuilding a broken one. Start with a motor that is in good shape. They just aren't rare enough or expensive enough to rebuild one with the intention of it performing in stock form.

The only reason to really do a rebuild on the L98 is if keeping it numbers matching is a concern. The only reason to rebuild the LT1 is if you planned to rebuild the motor no matter what (for instance in a performance application), and the bad stock parts wouldn't matter anyways.

If your looking for a motor that performs like a stock L98 or LT1, just buy a good one and be done with it.

 

There is nothing "wrong" with the LT1. The reason it only had 5 years of production was because the Gen 3 sbc was ready to debut. The Gen 3 is better in EVERYway. I can think of nothing a Gen 1/2 will do that a Gen 3 isn't better at. GM only spent a little on the LT1/4 because it shares 90% of its parts with a standard SBC. If you drill a hole in the intake you can even use distributor. People have put LT1 heads on a sbc, and if you wanted, i'm sure you could put SBC heads on a LT1 with minor mods.

However, the LT1 has several advantages over a TPI system. The intake is good well into the 11's with no mods. Most guys don't even touch the LT1 intake because the gains to be had are minimal.

The heads stock flow much better than L98 heads, and are easier/cheaper to port as several well known head shop have proven heads/cam packages. Lloyd Elliot is one of them, Advanced Induction is another.

The last advantage is the Fuel Injection system. Its easier to tune, easier to FIND someone to tune it, and offers better control of fueling on a day to day for a daily driver.

I have a B-body LT1 swap, it drops right in, no special mounts or anything so the physical portion of the swap is a direct fit. That means iron heads so roughly the same compression as an L98, a much smaller cam profile because it was a B-body motor. Yet, I am running easy 13.5's all day long at 102mph or so with nothing more than a cold air intake, headers and a cat-back. The cut-out made no difference on several back to back runs.

And all the while in the only times its been to the strip the PCM was pulling 5* timing due to false knock. I've fixed that with a LT4 knock module and haven't gone back yet but I will.

This is a full weight car too.

If I had the F-body cam, and no false knock I bet it would be bottom 13's all day long. As it is I run right next to stock LS1s, and have a slight advantage down low thanks to the super small cam. Throttle response down low feels better than a LS1, though LS1s are def the better motor.

I would also like to point out that the "reverse" cooling isn't much of a negative point. I don't see any advantages to it really, but its not hard to bleed, and I've never had any problems with my optispark either.

I average about 17mpg with out TC lock-up or over drive. This means about 3500rpm on the highway, and it still gets good economy for that.

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That said, a 5.3L Gen 3 swap is the hot-ticket right now. Cheap, plenty of power, its got great heads out of the box, so a mild cam brings major gains. HPTuners is also super easy to use. The stock harness is easy as pie to convert to standalone, it pretty much already is.


If money is no object then it doesn't matter what you drop in there, because SBC, LT1, or LS1 its GOING to make serious power. But when constrained by money the LT1 makes a solid investment.

 

Ok then, like some of you are saying the 5.3 swap is one of the big things to do to our cars due to them being part of the LS family, im kinda familiar with what all i would need to buy or do if is was to say put a LS1 in my car, so my question is would it be the same as putting an ls1 in a third gen or would i have to do otherthings to make the 5.3 work?

 

one last thing, would ls1 parts bolt right on to a 5.3?

 

Yes.

But your transmission won't.

You can get a 5.3 engine for pretty cheap, but by the time you add f-body oil pan/pick-up/tray, front accessories, intake manifold and fuel line, PCM & harness, and transmission (or a torque converter made to put a TH700 on an LSx engine), you could probably buy a drop-out f-body LS1/PCM/harness/transmission for the same or less money.

 

depending on how good you are at haggling, and what you have available for trade, sometimes a 5.3 can be cheaper than an LS1 dropout, but that route typically takes longer than an LS1 dropout, because you have to wait for the deals. me, I wouldn't consider anything less than a LT1 unless you've got a 1LE that you want to keep all original or something to that effect, but then you wouldn't be posting here would you!