Originally Posted by flyitlikustolit

So I'm working on another 3rd gen, this time an 85 IROC. It has the louvred hood, and it will be getting a 5.3 and a 4L60E. I understand why the truck accessories are a pain, and why fbody accessories are preferred. what about A/C? what is everyone doing for A/C brackets and which compressor is the easiest to use? I was thinking I could use an 88 Camaro V8 compressor, as it has a serpentine pulley and is intended for passenger side mounting, and using ICT or LSSimple brackets. Will those work under the louvred hood? if not, will the Fbody A/C brackets work? or are they just like the trucks, mounted low and in the way of the K-member?

Originally Posted by Greg Jurgensen

i have a truck 5.3 vortec that i am wanting toput in my trans am 3rd gen against my t56. i am having a little trouble with wireing. i have the complete harness all the way to the bulkhead connector. i pulled motor from a truck that had been swapped a 1997 silverado. im not sure what needs to be ran from my trans am bulkhead connector to the wires at the trucks bulkhead connector. i can also send photos of what i am working with.

Originally Posted by Greg Jurgensen

i am not sure where to find these forums anyway you could link them for me please?

Originally Posted by Greg Jurgensen

I am currently putting a 5.3 votec in my 1985 trans am. I have both bulkhead connectors infront of me. I am not sure what need to be wired where our if it can be done. Any help would be greatly appreciated!

Trans am bulk head connector

Fuse box top with diagram

Bulk head connector from 5.3 to truck

Fuse box bottom

Originally Posted by punkmaster98

Originally Posted by Greg Jurgensen

I can't seem to find what I need there. A lot of helpful info just not what I need to wire to what

Originally Posted by SheldonZ28

Hey Everyone.

I See alot of questions regarding these engines, so i figure ill post some info based on personal experiences on putting a 5.3L into my iroc-z. This is based on physically fitting it in, ill make a wiring thread next. Im going to be referring everything to fitting in a stock engine bay, oem hood etc.

Truck motors are common to swap due to their cheap price and extremely large avaliability.

Intake: The truck intake is too tall to fit under the stock hood of a 3rd gen. The truck intake must be replaced by a LS1/2/6 intake. If swapping to an LS1/6 intake, you must be aware that you need to use LS1/6 injectors & Fuel rails which ise a different injector plug then what is commonly used on truck harness's. the use of an LS1/6 intake however, allows the reuse of the truck throttle body (78mm). LS2 intakes have the correct injector plugs, however LS2's have specific fuel rails, and use a 90mm throttle body. The corvette throttle body may be used in a Electronic throttle truck harness application, otherwise an aftermarket 90mm cable throttlebody must be used.

Accessory Drive: The truck accessory drive will fit into the car, however, the high mount alternator will hit into the hood. There are several people on LS1tech who have fabricated custom brackets to lean the alternator just enough for hood clearance, and this can be acceptable to close the hood. However, the second issue with the truck accessory drive is that the upper rad hose inlet points upwards, which hits into the LS1/2/6 throttlebody which makes them un usable. I decided to replace my accessory drive with an f-body setup. This required: Crank pulley, Waterpump, tentioner, powersteering pump, PS Bracket, Alternator bracket, Alternator, Idler pulley & Belt. The truck alternator physically fits into the f-body bracket, however it is much larger then the f-body unit and hits into the steering center link. The truck engines come from the factory with a boss on the side of the motor for a bracket, however it is not drilled, or tapped. To do this you need a M10x1.5 tap & drill, you must place your bracket on with a bolt in the lower hole, then start drilling. After you have a nice pilot hole, you can remove the bracket and drill. BE SURE TO DRILL STRAIGHT! There is a third mounting hole on the alternator bracket that the truck motors have no provisions for, so only 2 holes can be used. The back support bracket may be retained from the f-body alternator. Everything else is a straight bolt on.

Motor Mounts: The OEM Truck motor mounts are an odd shape for sitting onto the frame of trucks. They simply dont fit in our cars. F-body clamshells or LSX Adaptor plates must be used with the spohn mounts or stockers.

Oil Pan: The truck oil pan is a deep sump system, which would be excellent if it could be used in the f-bodys. However, the pan hangs about 3" Below the k-member and unless you lift the car several inches, is a recipe for disaster. Do the right thing, swap the pan out for an f-body pan. You need the pan, windage tray, and pickup. I reused my o-ring from my stock pickup. I dont advise you do this, go purchase a new one. I got lucky on this.

Ignition System: The truck ignition system is a very capable setup, and is a little hotter then the Car ignition system. They sit higher and work best with a/c setups. They however wont work with Corvette fuel rail covers due to their shape.

Exhaust Manifolds: The truck exhaust manifolds also will not fit in the 3rd gen f-body. the collectors come out wide and crash into the front frame rails. I looked at the position of the collector and thought i could outsmart them by cutting them off and turning them. Turns out i was wrong, they flat out wont work. You can use stainless works LT's or F-body manifolds. I coulnt afford the LT's and didnt want manifolds so i fabricated my own headers.

I think that just about covers everythin that needs to be changed to fit them into an f-body. If anyone has questions, feel free to ask

Originally Posted by Martinezkustoms

Originally Posted by Ian Markey

I am having a hard time getting my 5.3 into the car straight. I bought adapter plates from summit racing and the engine wants to be crooked. The plates allow use of the clam shells and the motor should sit on the oem mounts but it's not lining up properly.