LS3 Clearance Issues to Frame

[Toddoky]

Perry, the fore/aft engine position you'll achieve using the Hooker 68-72 A-body engine brackets depends on which set you use (there is a forward-bias set and a rear-bias set) The rear-bias set locates the engine/transmission mating plane in the stock Chevelle/SB Chevy location and the forward-bias set moves the engine/transmission mating plane forward by 1.25" from that location.

For some better understanding of the geometry involved, you need to remember that an LS engine block is 1-3/16" shorter than a SB Chevy engine block (and the length is all missing off the back end of the block), so you can move the engine/transmission mating plane forward by up to 1-3/16" from the SB Chevy location before the front face of the LS block, or the LS cylinder heads move farther forward in the car than where these reference points were in the original SB Chevy installation.

The caveat here is that both the forward-bias and rear-bias Hooker engine brackets have fitment benefits over the other related to transmission and accessory drive fitment, so if you are going to move the engine rearward to provide more clearance for your steering, it may cause you to encounter some sheet metal re-work in the transmission tunnel that you wouldn't need to do if you were using the forward-bias engine brackets, depending on the specific transmission you are using. The old-school Power Glide, TH350, TH400, 2004R etc.. transmissions won't give you any grief with the rear-bias engine brackets, but a 4L60-4L70, 4L80 or T56 will if you are trying to end up with desirable U-joint working angles.



The engine mounts used with the Hooker engine brackets are GM 4th-gen F-body mounts, which poly inserts can be purchased and used with the stock cages for those mounts. Yes, the Hooker engine bracket set-up is based around using the four forward bolt locations on the LS block as they are the only ones that exist on all LS blocks.