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Just as the title says, I am in the process of of dropping in a Gen v lt1 into my 4th gen. I also have the 8 speed auto, with complete harness and ecu/tcm. I officially started work on the car this week, Got the entire car gutted, only thing left for the most part is the dash. Cleaned up the engine bay, as well as repainted it. I am by no means a painter, but looks a lot better than it did. Should have the motor and trans actually sitting in the car with in the next few days.
Had the pan off to inspect the rotating assembly, but all sealed back up and ready for install.
It’s good to see someone pursuing this swap. What are you using to mount your engine?
I am using some clamshell mounts that holley makes. They are called blackheart mounts I believe. Poly inserts, Steel shells. They were 30 bucks each I think.
I’m glad you found them, I was going to suggest them if you hadn’t. I’ll be following your progress to see how things go for you. In looking at you photo it seems you may have the inserts flipped in the cages. The longer end of the insert should point towards the front of the car on the passenger side of the engine and towards the rear of the car on the driver side of the engine. I know it sounds goofy, but it follows the way GM designed the mounts in the 4th-gen F-Body LS1 cars.
I’m glad you found them, I was going to suggest them if you hadn’t. I’ll be following your progress to see how things go for you. In looking at you photo it seems you may have the inserts flipped in the cages. The longer end of the insert should point towards the front of the car on the passenger side of the engine and towards the rear of the car on the driver side of the engine. I know it sounds goofy, but it follows the way GM designed the mounts in the 4th-gen F-Body LS1 cars.
I wish I would of read this last night, figured this out the hard way while trying to set the motor in today lol. Also, G Atsma has mentioned that you work for Holley/Hooker, I still have the oem oil pan on the motor, the only issue that I seem to have with clearance is with the rack and pinion. If it the rack was 1/2 an inch lower, or the pan was 1/2 an inch shallower throughout the front portion of the pan, everything would clear. Is the swap pan that you guys have designed with that in mind?
Originally Posted by G Atsma
OP- Not sure if you know it but Toddoky works for Holley/Hooker. You have a good set of eyes watching this build! If he gives any pointers, use 'em!
Worked on the car all day today. Since I am dropping the motor in from the top, if anyone decides to try this in the future, you will probably have to pull all the accessories of the front of the engine, as well as the intake and exhaust manifolds. Dropping the k member and the use of a lift is the preferred method of installation, but I do not have that option as of now, so I put the car on jack stands, and lowered the k member as far as I could to get the oil pan to clear, and the top of the engine clear the cowl. Removal of the rack and pinion will make installation 300x easier also, as it took me about 2 hours to figure out that it touches the pan just enough that no matter what you do, the motor mount holes will never line up. But, Once I got that worked out, the engine looks rather happy in the engine bay.
The Holley 302-2 LS oil swap pan was used as a fitment gauge to design the Holley 302-20 LT swap oil pan. Even so, the oil passage cavity hump that is required to be in the center of the front end of the 302-20 makes it taller than the front end of the 302-2 and 302-3 pans. That thickest section height of the front of the 302-20 pan is 1.79”, so you can compare that to the front height of your current pan to determine if it will provide the steering rack clearance you need. If by itself it won’t, you may need to combine its use with some shims under the motor mount stands. Your crankshaft height with the Holley mounts is now the same as a stock 4th-gen LS1 installation, so you should be able to raise the crankshaft height 3/16”-1/4” without having to do anything other than use an adjustable torque arm arm in the rear to readjust your rear pinion angle if needed. Your other option would be to lower the steering rack height, but that would be a lot of work and also require you to space your outer tie-rod ends downward at the steering arms to get your bumpsteer geometry correctly again(plus you have to go through the measuring process to determine how much spacing is required at the tie rod ends.
The Holley 302-2 LS oil swap pan was used as a fitment gauge to design the Holley 302-20 LT swap oil pan. Even so, the oil passage cavity hump that is required to be in the center of the front end of the 302-20 makes it taller than the front end of the 302-2 and 302-3 pans. That thickest section height of the front of the 302-20 pan is 1.79”, so you can compare that to the front height of your current pan to determine if it will provide the steering rack clearance you need. If by itself it won’t, you may need to combine its use with some shims under the motor mount stands. Your crankshaft height with the Holley mounts is now the same as a stock 4th-gen LS1 installation, so you should be able to raise the crankshaft height 3/16”-1/4” without having to do anything other than use an adjustable torque arm arm in the rear to readjust your rear pinion angle if needed. Your other option would be to lower the steering rack height, but that would be a lot of work and also require you to space your outer tie-rod ends downward at the steering arms to get your bumpsteer geometry correctly again(plus you have to go through the measuring process to determine how much spacing is required at the tie rod ends.
I believe a shim under the stands will probably be the easiest route to go for sure. I thought I was gonna be slick and modify and ls fbody pan, until I found out about the resigned pick up tube lol. But I will measure the oe pan if the shims do not work correctly.
Made some progress over the past few weeks. Was able to grab a k member from one of my buddies. Was missing the motor mounts, which was not a bad thing, but BMR is local to me, so they were able to hook me up with those. As for modifying the k member, I had to flip the rack mounts from the top of the cross support, to the bottom, and I also moved the engine back as far as I could in the engine bay. Also, oddly enough, the 8l90 fit in the tunnel with 0 modifications. Not even 1 tap with the smallest hammer lol. I still have to get a driveshaft made, but that is pretty straight forward and simple. As of now, I am in the wiring phase, and have to finish modifying the headers. For now, I am just re flanging the ls fbody headers for now.
The trans fit! That’s awesome lol. Is it at some crazy angle or did it fit correctly? The 8speed is huge. I did a 4l80e in my 4th gen and it needed a bunch of big hits with a big hammer. I just Put a 10speed in my 68 and it needed surgery.
The pan does hang down a little, so I am in the process of coming up with some sort of skid plate for it. Was one of the first things I noticed once it was sitting in there. I am still unsure how the 8l90 fit with no modification to the tunnel. I am just as surprised as you guys lol. I will take some more pics of everything when I have it on the lift again, which will probably be this weekend. Trying to get the wiring and the ecm figured out. I have a complete harness from the swap car, which was a 2017 camaro ss, and I have all the wiring diagrams from a friend at gm. So, I am in the process of making my own standalone harness.
03-03-2019, 12:33 AM
Gen V LT1 $th gen fbody swap! 
