LT1-LT4 Modifications 1993-97 Gen II Small Block V8

The 1997 F-body LT1 can't be swapped with other year LT1s?

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Old 06-29-2018, 02:42 AM
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Unhappy The 1997 F-body LT1 can't be swapped with other year LT1s?

Hey guys. To make a long story short, what I thought was a bad optispark problem has also revealed that my computer was also working with a bad motherboard so, I must have been driving the engine lean until it really got bad months back and now my pistons are warped, "egg-shaped", according to the mechanic working on my car these past months.

So, I need a replacement engine and I am trying to do this on a budget and as fast as possible to get my car back. Pretty much any low mileage junkyard/salvage Firebird/Camaro/Corvette LT1s have been picked over and the mechanic did find someone with a 1995 Roadmaster LT1 with low mileage and we were going to use this engine until someone told him that it won't work, even flashing my rebuilt PCM with the Roadmaster program. I am forced to use a 1997 specific engine only to my car?! Can someone explain to me why? I understand that in order to use the stock program for your PCM the engine must match that year for the program, camshaft and heads. My Trans Am is used as a daily driver and actually a B/D-body LT1 may be better suited for my daily driving but why the heck can't I use a pulled 1995 Roadmaster LT1 with the correct optispark in my 1997 F-body with T-56 transmission, even to have the PCM flashed for the engine?
Old 06-29-2018, 07:47 AM
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I'm not 100% on the specifics but someone else will chime in and verify. You can use it, you'll just have to change a few things over, namely I believe the front cover, reluctor ring, balancer hub and balancer, and I believe you will have to remove two plugs on the side of the roadmaster block and put your knock sensors in.
Old 06-29-2018, 07:52 AM
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96 and newer LT1 cars are ODB2.
95 was the last year of ODB1 for the LT1 Fbody.

Not sure about the roadmaster motor but there are large difference between an Impala SS LT1 and Fbody LT1.
The LT1 in the Impala has iron heads, a milder cam and many other little tweaks. Not sure about the optispark differences.

There are plenty of wrecked Fbody's with complete motors and wiring in parts yards/craigslist and ebay.
Consider that or just rebuild your current motor.
Old 06-29-2018, 05:20 PM
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You should be able to swap all the necessary parts from the original motor to make it work with the one from the b-body. Shoebox made a list in this post you will need . I am also pretty sure the b-bodies switched from the spline driven opti least one model year before the f-bodies.
Old 06-29-2018, 07:33 PM
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Originally Posted by biketopia
I'm not 100% on the specifics but someone else will chime in and verify. You can use it, you'll just have to change a few things over, namely I believe the front cover, reluctor ring, balancer hub and balancer, and I believe you will have to remove two plugs on the side of the roadmaster block and put your knock sensors in.
I also read that the coolant temperature sensor is located on the passenger side cylinder head versus the driver side as on the F-body, so the plug would have to be extended and cloth taped to the wiring harness and guided to the sensor without making contact with the exhaust manifold/header. Okay, so worst case some swapping of parts from my dead engine must be done to at least in idea get the Roadmaster LT1 engine to work. I also read about a guide ring being needed for my T-56 transmission?

Originally Posted by Z28tek
96 and newer LT1 cars are ODB2.
95 was the last year of ODB1 for the LT1 Fbody.

Not sure about the roadmaster motor but there are large difference between an Impala SS LT1 and Fbody LT1.
The LT1 in the Impala has iron heads, a milder cam and many other little tweaks. Not sure about the optispark differences.

There are plenty of wrecked Fbody's with complete motors and wiring in parts yards/craigslist and ebay.
Consider that or just rebuild your current motor.
Yeah but I am taking a chance with a high mileage engine and not knowing it's maintenance history. I could end up with an engine that was abused and received annual oil changes. I am so close to tapping out my savings account after all of this that I NEED to have a quality engine given the money spent on the rebuilt PCM which was done professionally by a company based in Texas. Any kind of modifications I had in mind for next year are now put on hold. I just want a reliable engine and to get my college done with and hopefully to build back my savings while working and then interning.

With regards to the B/D-body LT1s, yes, I know the cam is milder, but since I have been obsessed over more lower and mid-range torque production after 10 years of owning my Trans Am, the milder cam may make me happy and improve my daily drive for cruising, especially to keep the car in sixth gear without downshifting. Yeah, it makes for lame performance but then again when can I safely enjoy high RPM torque production before I am speeding 20 over the limit? The tickets and points on my Class A commercial license are not worth it. So, I seek that torque experience sooner and at lower RPMs. Also, I had a debate about this on another forum, but the iron heads may also be better for it's thermal properties which results in more complete combustion in the chamber, which can help improve fuel economy on top of the "tow cam" that the engine comes with. Furthermore, the iron heads allow more airflow than my aluminum heads so it may balance out at higher RPM in my F-body with better flowing exhaust than the B/D-body cars had.

Originally Posted by stevo9389
You should be able to swap all the necessary parts from the original motor to make it work with the one from the b-body. Shoebox made a list in this post you will need . I am also pretty sure the b-bodies switched from the spline driven opti least one model year before the f-bodies.
The 1995 Roadmaster should use the same optispark as my 1997. I am just wondering why someone said they have tried swapping these engines into F-bodies and they never worked. Immediately I thought, was the PCM flashed for the engine? However, my mechanic said they did flash the PCM and the engine still wasn't right. I don't know, it doesn't make sense, unless he didn't want me to downgrade my Trans Am WS6 to such an engine. All I can say is, this car is my baby and despite the intention to be a high performance street racer, even a high performance muscle car/street racer ends up being someone's cruiser or daily driver. The legendary Phoenix has to grow old and burn out but it rises from it's own ashes into something new. So, if this engine can be made to work with my F-body, I look forward to experiencing the new heart of my Firebird.
Old 06-30-2018, 11:36 AM
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as mentioned a 94-96 B-body LT1 can be swapped into a 97 F-body. Just use the reluctor and timing cover from the 97, hub & damper and accessory's & bracket from the 97 motor. yes the iron heads will be heavier than the aluminum but stock Lt1 iron heads flow better than stock AL heads. The temp gauge sending unit can go on DS. Just remove the NPT plug on DS head and put it in the open hole on PS iron head. Yes the cams are slightly different but I doubt a stock tune f-body pcm will care
Old 06-30-2018, 07:25 PM
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Originally Posted by ******
as mentioned a 94-96 B-body LT1 can be swapped into a 97 F-body. Just use the reluctor and timing cover from the 97, hub & damper and accessory's & bracket from the 97 motor. yes the iron heads will be heavier than the aluminum but stock Lt1 iron heads flow better than stock AL heads. The temp gauge sending unit can go on DS. Just remove the NPT plug on DS head and put it in the open hole on PS iron head. Yes the cams are slightly different but I doubt a stock tune f-body pcm will care
If the coolant temperature sensor can be moved over to the driver side then that will make things a whole lot better! Thank you and I WILL relay this information to my mechanic/engine builder. Hopefully he will be willing to make these changes and hopefully I will get my Trans Am back soon. I still think reflashing the PCM for the Roadmaster engine will be prudent to ensure the correct timing tables for the engine so that everything works flawlessly.
Old 07-02-2018, 10:23 AM
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you could just put the cam and lifters in from the F-body motor....

I really think using your current F-body pcm as is will be fine
Old 07-04-2018, 04:55 PM
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Originally Posted by ******
you could just put the cam and lifters in from the F-body motor....

I really think using your current F-body pcm as is will be fine
It depends on many things. I have since had my car taken to a different shop since the previous one is taking too long and I can't wait 6-months for my car! Basically the engine was given a bad bill of health and he even thought the cylinder head for #4 was cracked. So, this goes beyond replacing the cam and lifters and honestly I feel it is more economical if I have a whole engine swapped in from a dirt cheap '96 Roadmaster with "low mileage" versus having the engine rebuilt which could literally bankrupt me at this stage. Also, I want to be safe in having my PCM flashed for this engine. I am fearful of what will happen running a B-body LT1 with the F-body LT1 program and timing tables. I just want this done right the first time and not have to worry about it until I can afford to start modifying my LT1 further.

Yeah, the B-body camshaft may be dull compared to the F-body/Y-body camshaft but it would be best to give it a try and decide on whether or not I am happy with it or if I will be bugging members on this forum with "absurd" questions on how to beef up my LT1 with this camshaft. I assume to start by increasing the rocker ratio to 1.6 and then slowly having the engine built up from there. I always complained about wanting more off-idle and low RPM torque for the grandpa driving I do to avoid speeding tickets and because I like to cruise the highway in six gear without needing to downshift everytime I encounter a minor incline.

I can always ask for more performance but for now I need to keep everything on a budget if I wish to avoid tapping out my bank accounts.

Last edited by Phoenix'97; 07-04-2018 at 05:00 PM.
Old 07-04-2018, 05:23 PM
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A tuner would certainly know but I think your existing stock F-body tune will work fine with a stock B-body LT1. Just transfer over the TC, CPS reluctor, hub/damper, knock sensors from the 97 to the 95 B-body LT1

Not like the cam profile of the B-body vs F-body stock cams are that diffrent



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