Im putting an LS1 in a 1968 Firebird, and it had a TKO 600 behind a 326. I swapped the frame stands for Camaro stands.

So I started with ICT plates found out if i want to keep my TKO in the same position I need 1" set back adapter plates. Correct?

Then i ordered 1" Setback plates from TW fabrication. When i got these in it made me completely question the ICT plates, or possibly how i read the description of them. They say: "There are 4 positions for maximum adjustment of engine (from .100" forward of OEM bellhousing position [due to bolt interference, OEM location is not possible for any brand of flat style swap plates] ~forward most position shown in photos~, Secondary positions are: .600", 1.86", and 2.36" engine moved forward) "

So when i read this, it says all of the positions are forward of original SBC mounting position right? It really doesnt look that way when i compare to the TW plates i just got that are 1" set back only plates.




Based off of the only measurements i could find searching, stock location puts the bolts 1.75" to each side of this hole, so id assume this is correct at .75" away in order to get the 1" setback.

 

They are a bit confusing on their explanations. The .100 is basically the oem position and many people have used them to bolt up to stock bell housing locations with no issues. They are called 1" setback because when comparing an LS to a sbc the LS motors don't have that extra inch off the rear of the block so they need to sit an inch further back to bolt up to the sbc location. 1" setback and sbc location mean the same thing.

 

So their measurements are ~1" Set Back, then .600 forward of that etc...?

Still a little confused why the ICT is so much different than the other "1" Setback" Plates i bought then. According to their method they would be more like a 1.125-1.25" setback.