LSx installation questions from those that have done it...

[68GMCCustom]

I have a few questions before I order all of my parts for my new LSx motor and am hoping a few of you can help.

The truck accessory systems are plentiful and I believe I've seen a few installs using this accessory drive system. I'm curious about the others available, and if they fit with the various LS swap motor mounts on the market (ECE, CPP, etc.)

If you've installed an LSx motor and used an accesory system (f-body, cts-v, vette, gto, etc.) other then the truck system with high mount alternator, I'd like to here from you.

What accesory drive are you running?
Were frame modifications necessary?
Which mounting system (ECE, CPP, etc) are you using?


Also, for those with headers at least with 1 3/4" primaries or even 1 7/8" primaries...what are you running and with what mounts?

Thanks in advance!

[RaceAGMC]

I used the factory truck drive accessories and used the CPP mounts and LSX plates and install was a breeze. Although, I have not put any headers on yet, but i plan on using the Throley swap headers cause I do not want to have to modify the frame. I have heard a lot of guys using F-Body headers with larger primaries without having to modify the frame.

Anyone else with some insight please chime in.

[junkman]

I have a 5.3, just used 1" setback plates on otherwise stock mounts. Cheapo ebay stainless f-body headers cleared the frame fine, did pie cut the collectors to angle them in some.

[68GMCCustom]

Thanks guys. I have the truck systems main piece of bracketry (it holds alt. and p.s.) but would prefer one of the car style systems. I think they look a bit better, and since I'm running an aluminum intake w/carb I don't want the alt. up so high in front of it. I just need to know that the lower position p.s. or alt. will clear, as will the A/C compressor.

My motor also has the big port heads, and I'm working on going with a cam to get the most from these heads. Everything I've read or been told tells me that I need large tube headers. Realistically I could even go with 2" primaries...but I'd like to be able to install/remove the plugs easier and not burn up the wire so I'm thinking 1 7/8" or 1 3/4" at the smallest.


Also...is everyone getting new radiators with inlet/outlet on the passenger side? Or running a long upper hose (dodging alt. and serp. belt?) with the original radiator?

[junkman]

I don't think you are going to be able to get the a/c compressor in there without doing some cutting. I just used a complete f-body radiator/fan assembly. Easy to mount and all contained in itself. I just used stock radiator hoses for the 5.3 truck, if you were using the f-body water pump, I am sure you could just use the f-body radiator hoses. I would say the hoses that came from whatever the genIII motor came out of would work with your stock 67-72 radiator as well. The upper runs across to the driver side on those vehicles anyway, and the hoses are made to clear the accessories. Helped a buddy with a 5.3 in a 85 truck and used the stock radiator with the 5.3 trucks hoses.