I have been convinced by many of people to swap out my TBI for a beautiful LT1. Now what would be a good price? should i buy new or used? if used should i rebuild? how much would the avg. rebuild b? would my 3rd gen M5 tranny hold up with it for long? Does neone have any opinions or ideas for me?

 

Check e-bay for pricing. You will have to convert to t-56 tranny. 3rd gen M5 will not fit or stand up to the higher hp/torque. Plan on swap being in the 3000-3500 range. Mods will puch this figure higher.

The corvette LT1 is more desireable. 95 and up engines had a vented optispark so they are more desireable as well.

 

Yes it will on both accounts.
1. It bolts right up.
2. I've had a T-5 behind a estimated 400hp LT1 for 2 years now and only had to rebuild it once because my clutch went out and it chewed up the synchros in the process. It can withstand quite a bit if you don't do high rpm clutch dumps or try to launch on slicks.

The best engine to get in my opinion is a '95 Vette LT1, has the accessories mounted up top and has OBD1.

 

Thanx alot for that correction tex! that helps out alot, but i found a 94 firebird LT1 fo $750.00. do u think i should go with that? thanx again man he had me real scared!

 

$750 sounds kind of cheap if you ask me. Is it a complete engine with harness, ECM, and accessories or just the engine itself?

 

So which units were not interchangable? I distinctly remember an issue with the inupt shaft being different for one of the swaps.

 

Thats the V-6 T-5, the one behind 305's bolt up no problem. You're thinking of trying to use teh v6 T-5 behind a v8.

 

yea he says it has everything! but the harness and i hear that it is a good deal

 

how much is a TBI with 121k on it worth on a trade in for that LT1??

 

$750 with everything but a harness sounds like a very good deal, I'd just check over the engine before you do the swap, might want to pull a main cap and rod cap, check the bearings and stuff just to make sure it doesnt need new parts.

A 305 TBI for a tradein? I wouldnt give more than $100 for one, they're pretty much worthless as far as I know in that way. might want to check and make sure though, but I don't think you'll get much.

 

ok that sounds good man thanx alot, how much do u think a T-56 tranny would b? thats what im going after next... unless u think our T-5s r just as good...

 

for a stock to mildly modified LT1 the T-5 is fine. If you ever plan on doing serious mods beyond bolt-ons, definitely get the T-56. Really the only reason we kept mine was we didn't want to spend another $1000-$1500 for a stonger transmission when, if we needed to, we could rebuild the T-5 for just a few hundred. Originally I didn't plan on doing many mods, but now that I'm looking for more power, the T-5 isn't going to work much longer.

Another option, if you already have a good T-5, you can keep it and use it fine until you start doing a lot of mods. Then, depending on the cost of a T-56, you could either go ahead and do the trans swap, or upgrade the T-5 with the new G-Force parts and make it as stong if not stronger than a T-56. Something else to consider. Doing it this way will keep your initial costs down so that you can save up for a T-56 later.


To answer you original question, a good T-56 will probably run you about $1000 with hydraulics and shifter. Probably would want to get a good aftermarket clutch. I've had a Centerforce Dual Friction now for about a year and a half and its been great, awesome holding power.

 

hey man thanx alot!! i really appreciate all of ur help do u have an AIM account? it would b easier to talk that way if possible, mine is lilc1511... thanx again man

 

sorry man, don't have an AIM account. e-mail me anytime you want though.

 

alright man thanx whats the e-mail?

 

I finally got a LT1!!!! I'm very excited to get it in, it has 120k on so do you guyz think i should rebuild before i put it in or just run it for a while and then rebuild?

 

120k really isn't that high for an LT1. Mine has over 60k on it and I swear its still got the factory hone marks in the cylinder bores. I would pull the oil pan and heads off and check the clearances on the rods/mains/bores, if those are good, put it back together and don't worry about it.

 

Thanx man, hey Tex what kinda exhaust you run? I want true dual, do you have true?

 

If it has 120K on it you may want to do some preventative maitainence on it while it is out. It could save you from serious headaches in the future. I would replace the opti spark right away, even if the current one works okay. They have a habbit of failing instantaneously especially with high mileage. If you plan on this motor becoming a beast you may look into getting that high performace opti they make now. It is 700 bucks but will last forever and has a great warrenty unlike the GM piece. You may also want to get an electric water pump to aid in the cooling, free up some power, and get rid of the old one that could fail. I would also spend some extra money to have the heads pulled, cleaned up (maybe good time to port, LT1 heads are killer when ported) and replace the head gaskets, and the intake manifold rear seal. LT1's are notorious for having a bad intake seal at the rear of the block. Make it easy on yourself and take care of this stuff now. You will have a really good and cheap engine after these things that will be really reliable for you down the road. Even adding a cam and new springs would be a good investment while the motor is out. You may have to save up a little more (about another grand) but I think you will be happy with the results. Plus the added time will allow you to get the right wire harness along with a re-programmed computer. LT1 edit it the way to go but PCMforless does pretty nice (mail order) work for LT1's and LS1's for only 100 bucks or so.

 

Well my LT1 is a 94 so I think it is optisparkless ... right? NEWAY I'm trying to save for college right now so i may pull the heads and clean the myself, but i won't port em and what not yet, i just dont have the money, I would rather do it down the road when im a little richer, But i will definately do the preventative maintinence because i want this engine to last me quite a while before i rebuild it, i would like a good 2-4 years out of it. I thought you just had to rewire the harness and computer and what not, i dint kno you have to reprogram and ****, i don't kno how to do that ****! there goes another hundo...

 

No no you don't need to reprogram it unless you add heads and a cam and want the VATS and a few other things deleted. If it came out of an auto car you have to have the auto tranny stuff deleted and what not. There are a few other things I think as well but cannot remeber off hand. All LT1's came with the opti spark so you are stuck there. The 1995 and later ones came with a vented one to help wick out moisture. So you may want to convert to one of these since your is a 94. These things are very sensitive and you can't even get water under your engine bay or it could go out.

 

90, I'm running Heddman shorty headers and y-pipe, gutted cat, 3" I-pipe, stock GM muffler (don't ask).

Like Shifty said, ALL LT1's have the crapti-spark, but the '95's and up have a better one. I've run my car through heavy rain before and haven't had any problems with it. I might get the rebuild kit they make that replaces all the internals just to get new parts in there, but there is no telling how long that would last. The aftermarket opti is definitely a nice piece, but really not worth the money.

As far as preventative maintenance, bascially I would replace ALL of the gaskets and seals to begin with, definitely save up for a new Opti just in case, you may never need it. An electric water pump is really something you have to decide about. On one hand, it definitely helps out with any cooling problems, but at the same time there have been many stories of guys with electric pumps having them fail on them at very bad times, and since its not driven by the engine, it stops completely. The stock pump should probably just be replaced with a new one while you have it off to replace all the gaskets.

 

so wait, wait, i cant wash my engine and what not with degreaser and water when its gets a little dirty cuz of optispark!?!!?! I hate when my engine is dirty And yes it did come out of an auto tranny, where do i get that stuff deleted? As for ehaust i think im going to go straight pipes, but with a muffler... maybe side pipes haven't really decided totally yet, i wait to see how much money i have then

 

You can only wash your motor with a wet/damp rag and thats about it. DO NOT spray a hose in there or you will be sorry. The opti is the devil trust me. And you will need to get the computer reprogrammed if you are going with a manual tranny.

 

where do i get it reprogrammed at?

 

Not 100% true. The car will run fine with the auto program, it will just keep throwing codes for a transmission that isn't there and will idle a little low.

There are a number of mail order places that you can check out to get it programmed. I used Brian at pcmforless

Another one I've seen advertised on camaroz28.com that seems to get good reviews is madz28

They both have a number of different options for getting your ECM programmed correctly.

 

Ion at madz28 did mine and his work is fantastic. I used a manual trans with an auto pcm and it did run, but like mentioned, it did throw codes.

 

Listen to ShiftyCapone on this one. He is absolutely right. I have had bad experience with the opticrap as well.

 

i guess maybe i will wait a little while to put it in till i have some more money to get some of these extra things...