Opinion On Engine Swap
Thread Starter
Heel & Toe
Joined: Jun 2006
Posts: 22
Likes: 1
Opinion On Engine Swap
I was looking for an opinion on swapping engines in my 77, i can get my hands on a L98 out of a 88 GTA trans am or a 95 LT1 out of a buick for about the same price and with roughly the same miles. The question is with limited mechanical background and the 200r4 i already have to install in the car which is the easiest to swap in and which motor is the most worth while? I would be freshening either motor and hp while is a concern i have read enough mods on this site to far exceed my goals with either motor. sorry for the long post but cost and ability are also a concern, so any and all opinions are appreciated. thanks
Team Owner
Joined: Oct 2004
Posts: 23,831
Likes: 10
From: Springfield MO
St. Jude Donor '07
I was looking for an opinion on swapping engines in my 77, i can get my hands on a L98 out of a 88 GTA trans am or a 95 LT1 out of a buick for about the same price and with roughly the same miles. The question is with limited mechanical background and the 200r4 i already have to install in the car which is the easiest to swap in and which motor is the most worth while? I would be freshening either motor and hp while is a concern i have read enough mods on this site to far exceed my goals with either motor. sorry for the long post but cost and ability are also a concern, so any and all opinions are appreciated. thanks
As far as the engine goes, I'd take the LT1. It's a bit more advanced than the L98, and the manifold flows more air than the TPI.
Pro
Joined: Nov 2007
Posts: 741
Likes: 1
From: Woodstock GA
Either one is going to be about the same difficulty to install - have to wire up the engine computer and set up the fuel system properly. I'd recommend using the 7727 Weatherpack engine computer - it uses the same memcals as the more common 7730 non-sealed computer, but you can mount it in the engine bay. You can find a 7727 in some V6 Pontiacs.
As far as the engine goes, I'd take the LT1. It's a bit more advanced than the L98, and the manifold flows more air than the TPI.
As far as the engine goes, I'd take the LT1. It's a bit more advanced than the L98, and the manifold flows more air than the TPI.
To be sure the Buick has the LT1 and not the smaller version, look for "327" cast into the side of the block. If its there, its an LT1 5.7 .The LT1 will make more power for less money than the L98, and will bolt up fine to your transmission (though you will need a '93 F-body throttle body for the TV cable, or an adapter from Street & Performance).
Team Owner
Joined: Oct 2004
Posts: 23,831
Likes: 10
From: Springfield MO
St. Jude Donor '07
If you're going to go LT1 (my recommendation), by all means use the stock PCM that goes with the engine. I don't believe the older PCMS referenced will run the Optispark distributor, and the stocker would be plug and play. PCMSforless.com will reprogram it to delete whatever you need to, and compensate for any mods, for about $100.
To be sure the Buick has the LT1 and not the smaller version, look for "327" cast into the side of the block. If its there, its an LT1 5.7 .The LT1 will make more power for less money than the L98, and will bolt up fine to your transmission (though you will need a '93 F-body throttle body for the TV cable, or an adapter from Street & Performance).
To be sure the Buick has the LT1 and not the smaller version, look for "327" cast into the side of the block. If its there, its an LT1 5.7 .The LT1 will make more power for less money than the L98, and will bolt up fine to your transmission (though you will need a '93 F-body throttle body for the TV cable, or an adapter from Street & Performance).
Le Mans Master
Joined: Aug 2003
Posts: 7,720
Likes: 12
From: Chattanooga TN
I would go Tuned-Port before LT1. Don't get me wrong, LT1 is a fine engine but the TPI can use all original accessories. Do a search on my username and TPI swap and you should find my installation "primer". Somebody else-DRJAY I think- wrote a detailed TPI install guide for C3 recently as well. Another reason to go TPI is that LT1 will have to be set up as either manual transmission or 4L60E automatic so the computer can't lock the converter like a 7730 ECM can. If you use the '88 motor, I would convert to speed-density to eliminate the MAF sensor. All you have to add is a MAP sensor and just don't plug in the 9th injector. Buy a harness and computer for a '90. Ask any questions you like of me and I'll do my best to help.
Thread Starter
Heel & Toe
Joined: Jun 2006
Posts: 22
Likes: 1
thanks for all the info. i am going to check out that lt1 more carefully and i need to think some more about this conversion. evrybody made great points but after some more research it sounds like the accesories are the biggest problem with the non vette lt1. also question about my fuel tank, does it need to be replaced with one with baffles or does it depend on weather or not i use an interior or exterior pump? i am sure i will have many more questions. thanks again
Pro
Joined: Nov 2007
Posts: 741
Likes: 1
From: Woodstock GA
Why are the accessories an issue? If the LT1 has everything there, you can make it work, though you may have to relocate the AC compressor. I have owned and worked on both TPIs and LT1s extensively, and MUCH prefer working on an LT1 (not even getting into the extra HP potential). The multi-piece intake is a PITA (seperate base,runners, and plenum) to work with, and to flow any decent amount of air you'll wind up replacing the base and runners anyway, or changing to a Stealthram or Super Ram. Your iron LT1 doesn't have the aluminum heads of the F and Y body versions, but the heads actually flow a little better stock than the aluminum versions. The Vortec heads everyone raves over are based on these heads, and they are far superior to L98 heads. No chips to burn, either. Also, I don't see where running an auto other than a 4L60E is an issue...he probably already has the lockup switch wired anyway, and people run non-electronic transmissions behind LT1s all the time. If you need more info, go over to http://www.camaroz28.com , and check out the LT1 section. There are TONS of knowledgable people over there.
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Racer
Joined: Oct 2004
Posts: 439
Likes: 0
From: Mukilteo Washington
Both will require a fuel tank/pump mod.
I'm doing a 77 that has a mild 383 TPI LTR Accel set up. I started with a MAF system and changed to the MAP out of a 90-91 Vette, I have the weather pack, harness and ECM, I just couldn't figure out how to plumb that damn MAF sensor to my taste.
You can run a exterior or interior fuel pump with upgraded lines but I wouldn't let the tank get to low (no running on fumes). I'm drilling a 4 1/2" hole on the top of my tank to install a Tanks baffled fuel pump assembly. Cut and paste seams the only way this opens.
http://www.thedetailzone.com/Tanks Fuel Pump Install.htm
I have a new painless harness and other things for a MAF if your interested.
I'm doing a 77 that has a mild 383 TPI LTR Accel set up. I started with a MAF system and changed to the MAP out of a 90-91 Vette, I have the weather pack, harness and ECM, I just couldn't figure out how to plumb that damn MAF sensor to my taste.
You can run a exterior or interior fuel pump with upgraded lines but I wouldn't let the tank get to low (no running on fumes). I'm drilling a 4 1/2" hole on the top of my tank to install a Tanks baffled fuel pump assembly. Cut and paste seams the only way this opens.
http://www.thedetailzone.com/Tanks Fuel Pump Install.htm
I have a new painless harness and other things for a MAF if your interested.