mcdonaldheat

I am thinking of installing a lt1 with wiring harness and ecu from a 96 trans am into my 86 vette. My question is can I still retain my dash cluster. Will this work? <br />​​​

Sid.123

Good question... I await the vette guru's replys...

Cool Runnings

2 bolt main, 285hp?

mcdonaldheat

Actually, I think the l98 is a 4 bolt main. Not sure on the lt1 from the donor car.

Kevova

F and B bodies are supposed to have 2 bolt blocks. Only the Corvette gets 4 bolt lt1

Bagpype

I have never done an lt1 swap but I will tell you from swapping out one l98 for another, different l98 that the lt1 swap will be not a fun process.

Benny42

Put a cam and a miniram on your L98 and you have all the upside with no optispark or wiring nightmare. Easy as pie.

v8vette84

I did this on my 84'. LT1/T-56 swap. The process is not hard at all. I have no idea why I always read that Gen1 to Gen2 SBC swaps are hard because they are not.

If swapping a bad L98 for a good L98 is "hard" then you probably are not very mechanically inclined.... Just saying...

Anyways what I did was I used a stand-alone harness to the LT1 then I wired all the gauges to the harness or ran new wires. I also swapped out my atari cluster for a 97' Camaro Z28 cluster and just found all the pinouts and found all the connections I needed. The stand alone harness was WAY easier then using the factory engine harness and having to tie into it. The 84' uses an older smaller ECM that fits under the dash where the LT1 PCM sits in the engine bay and is much larger. The stand alone harness was WELL worth the money IMHO.

Also what Benny said is partially true, while sure you don't get the dreaded optispark (which I personally have had ZERO issues with and I have 3 cars that use an Opti and 2 buddies that also use optis on their LT's) you do have to set your base timing on the L98 which I am so glad to not have to do. Sure it's not hard but the opti only goes on one way so you can't mess the timing up. Also the L98 doesn't flow worth a crap so you would HAVE to go miniram and pony up some decent bucks for that and then you still have the crappy flowing heads to deal with. The LT1 overall is a better package than the L98 just like it should be (even though the L98 looks super sweet), better heads, intake, exhaust, PCM, far more accurate ignition system, reverse cooling heads for more compression and all with the benefit of running a traditional SBC bottom end. I'm not knocking the L98 but to say just a miniram and cam and your basically comparable to a stock LT1 makes no sense. It's the evolution of the SBC. L98>LT1>LS1>New LT1.

There's nothing wrong with a 2-bolt main. The only time you need to worry is when you are pushing 600+hp. There are TONS of 2 bolt main LT's out there making BIG numbers. Granted the 4 bolt is certainly going to be more stable at high rpms than a 2 bolt there is no point to going out of your way to find a 4 bolt block.

I would convert the Trans am harness to a stand alone and use it that way. Find a pinout for the L98 harness and tap into it to find the wires that feed your gauges. That shouldn't be too hard. Both the LT1 and L98 use the same values for the gauges so you don't need different senders or anything. Like if you swapped in an LS1 you would need different senders as the LS engines use different values to operate the gauges (ohms and voltages).

Also don't forget you will need to have the PCM tuned. Unless you are staying stock but the PCM will probably trigger the check engine as the OBD2 stuff is finicky.

Well after rambling on to answer your original question.... Yes you can retain your cluster.

Also take what you hear about the Optispark with a grain of salt. You only hear the bad on the internet and usually people who trash on the opti have never even owned one themselves...no joke... I got 165k out of my Caprice's opti before I changed it because the internet convinced me the opti was at fault for a misfire when it wasn't. I have 15k on the opti in my H/C LT1 and my other Caprice has 92k on the original opti with no issues. Plus I have 2 friends who run LT1's and they are doing just fine with their optis. Just STAY FAR AWAY from parts store optis. Buy Delco optis, they are the safe bet. Me personally I have old parts optis around that I steal the original Mitsubishi senors out of them install that sensor in a new housing and it works great. I bought 2 chandler motorsports optis, one that is on my Corvette and still kicking after 15k and another that I sold to a random person because I didn't need it. My buddy also had a 9C1 Caprice that had 260k on the original opti sensor as he bought it with low mileage. He only once replaced the composite body of the dizzy itself and resealed it. Never had a problem with it. Most opti haters buy cheap knockoff optis and them bitch when it ***** the bed....

Good luck and let me know if I can be of anymore help.

cv67

w/benny
waste of time most those projects never get finished

Re read his post take it to heart
Or get a converted LT1 intake put it on your L98 thank us later, make it easy on yourself. Dont do the conversion its simply not worth it
Sell the Lt1 get an intake, motor on.

v8vette84

I disagree; maybe YOUR projects never get finished but mine do!

I do agree you are better off converting an LT1 intake if you plan to stay L98. I started converted an LT1 intake for my 89' Camaro before I got the vette, now that intake just sits in my dads shop. Going from L98 to LT1 is Definitely worth it. It's a better engine all the way around just like the LS1 is better than the LT1. Plus you can pick up LT1's for like $100. I bought a complete LT1 for $50, no joke. They bolt right in as you can use the same engine mounts and transmission.

Plus the ease of tuning alone should be worth the swap if you plan on modding. I'm done with the burning chips crap...

I would swap in an LT1 all day long, I have seen first hand that they are reliable, make good power and get pretty decent gas mileage. (My 84' got 28mpg on the highway when I was running the cc503, ported heads, accompanying mods and a mail order tune)

Either way you will be happy but don't back away from the LT1 just because some people on here say to stay with the L98 because its "easier", more like they are lazier and don't want to do any work.... I personally enjoy working on my car quite a bit. I'm having a great time putting together my 383 LTx.

mcdonaldheat

Thank you everyone for the responses. Here is my dilemma with staying with l98. The engine overheated so I pulled the heads, upon investigation I found the heads cracked. So instead of replacing with l98 heads I did some research and decided to install converted lt1 heads and intake. Got it all put together with the small cap hei dizzy and now I can't get the fuel injectors to pulsate. Well I then noticed some water droplets under car so I found two hairline cracks in the block. So I am totally giving up on this block. Man the struggle is real. Thanks everyone.

v8vette84

Time to go LT1! Or just find another L98, shouldn't be too hard. You only need the block and rotating assembly. What are your plans?

mcdonaldheat

I already have a donor lt1, wiring harness and ecu. I have a hotcam and my intake and heads have all been ported. I am just not really sure how to make my cluster work with the ecu from a fbody?

mcdonaldheat

Can anyone answer this, when I initially installed the converted lt1 intake and small cap hei the fuel injectors will not pulsate. My fuel pressure is way down, 10psi, could this be the reason? I am replacing the pump but I wonder if I got some wiring crossed or not connected when installing the dizzy? I have tried two different regulators.

cv67

Your opinoin if you got a shop and its worthit more power to you
They are both 350s at the end of the day. This converion is over most peoples heads. My pos runs just fine.
half decent set of heads, lt1 intake his car will run just as hard, probably moreso nothing special about LT1 heads.

confab

My post will be lame-ish, but in an effort to help...

I was looking hard at an LS swap when I first got mine, (And I wish I had a link for you. But it has been so long I forgot.) and the people I spoke with at the time told me (paraphrasing) that you leave the C4 PCM in place, and it runs the cluster with the exception of the "Mileage stuff" (Their words???) and the other PCM is mounted remotely and runs the engine.. And both work.

So, I know it will work (at least based on the advice offered to me at the time.) and you might want to research LS swaps, which are far more common and will address the exact steps you must take to run both the engine and the cluster.

v8vette84

The LT1 can run higher compression due to the reverse cooling so therefore it certainly could make more power than a gen1 SBC part for part... This also makes the LT1 heads VERY special as you can't just bolt them on a gen1 and use them. It seems like maybe you don't know all that much about the LT1 but you sure are quick to discredit it...