nickp

iTrader: (2)

I have a few questions about setting up an LT1 motor plate in my 1995 firebird. i am planning to use solid factory motor mounts and a front motor plate, with no mid plate. i have a standard sbc 350 gen 1 block laying around and was wondering if i could use that to mock up for my motor plate install. some of u may be aware that u can only use 2 motor mount bolts per side when putting LT1 mounts on a gen 1 block, but they appear to be in the proper location. So my main question is, if I mock up the gen1 block to locate and weld in my motor plate, when i go to put my car together with my LT1 gen 2 block, will the plate be in the proper location? or do i need to search for a junk Lt1 block to use for mock up? next question would be, does anybody know where i can buy an LT1 specific motor plate (plate only)? the going rate seems to be $200 for a kit, and to me seems a bit pricey. i can fab my own mounts pretty easily if i can find a deal on just the plate. And last question, any tips or advice from those who have done a motor plate install? anything you would have done different? thanks.

nickp

iTrader: (2)

Should this be posted in another section? Anybody?

96LT1355Z28

iTrader: (2)

You might try posting on Yellowbullet. Sorry but I have never setup a motor plate so I don't have an answer for you. The blocks "should" be the same but I'd want to be sure if I were in your shoes.

orange88ls1s-dime

If you are running solid mounts there would be no need to use a plate. It would just clutter up an engine bay that doesn't have the room to begin with, especially if you plan on running optispark too. The reason you use a plate is to make for easy removal of engine and for better header clearance without mounts in the way. Stick to the solid mounts and you will be fine

96LT1355Z28

iTrader: (2)

I think Nickp is just using the mounts to hold the engine in place while mocking up where the plate will mount on the frame. Then using the plate and not the factory mount location. I think the question is will the LTX block be in the same spot using motor mounts and a Gen 1 block which he has now for mock up. Is this right OP?

fex77k

iTrader: (2)

I used a junk small block to mock up the lt1 front bolt holes. I run a front and midplate. I have cross braces that run up to the side mounts and right into my cage to limit movement from the drivetrain.

nickp

iTrader: (2)

Correct. I just need to make sure it will align the plate properly

thankyou fex77. i was hoping the offset was the same between the gen 1 and gen 2 blocks.

i have no core support in the car anymore and I figured a motor plate would be a good idea to help tie the front end together.

noice

First I put the mid plate in the car and the rubber rear transmission mount. The block I was using was a blown up bowtie block and the powerglide was an empty case. All together wasn't very heavy and held pretty close to where I wanted the front motor plate to line up. Used the cherry picker and a jack to get the exact position I wanted.


My car was previously running a BBC so I had to make some aluminum spacers about 1.5" thick to move the motor plate back to line up with a SBC/LT1 Block. I already had a BBC motor plate for my car so I cut the outside dimensions to that that. But all you have to do is get close with like a cardboard template or whatever and then start trimming so that you get the outside shape that you want. Then clamp it and and mark the holes with a punch or drill them in place.


As you said earlier the bottom two bolts just outside of the timing cover line up on a LT1 and a SBC. But as you can see in the picture, the top waterpump bolt lines up too. The plate is already cut out to my LT1 block but that is still the SBC in the car just so I could see what lines up. You can see I aligned the bottom of the motor plate to the same plane as the oil pan, makes it really easy to see if your are off a bit.

To make cutting out the middle of the motor plate is a little harder, you need three things, water pump gasket, LT1 Timing cover, and a piece of a bolt that is about 1 inch of thread and the rest of it pointed. It makes a punch that screws into the block. I screwed it into the SBC block I had until the tip barely stuck out and was touching the motor plate. Then if everything is how you want it, just tap the motor plate on the opposite side of where the pointed threaded piece is and it will make a perfect center punch where you need to drill out a hole. Repeat as needed for all your bolt holes. Then use the water pump gaskets to draw out your water pump holes. Then place the timing cover on and center it up properly. Try to keep as much material as possible between where the timing cover and the water pump holes are. You can see it got a little thin on the one I did. You should be able to make a nicer plate than I did, it was my first motor plate.

nickp

iTrader: (2)

perfect thank you. maybe ill price out a piece of aluminum and just make one