Hello.

At this time, I'm looking for an Iroc with a 305 and a T5. I want to swap both the engine and tranny for some more power, and of course a stronger tranny. I finally found a car, but I'm currently waiting for the price to drop again before striking (1986).

Engine: I have initially eyed the LS3. However, after additional research on the 3rd gens, I am starting to come at peace with accepting that it may be too much for the car itself (after all, 3rd gen is the "loosest" F-body made to date). So, I've begun looking at SBC gen 1 engines (pre LTx, those are technically 2nd gen, with LSx being 3rd gen). I've been looking at both the 350 HO and the ZZ4, both appear to be rather economical to me, and put out respectable numbers when comparing to what is to be replaced.

Regarding fuel delivery, what all would essentially have to be done? I've been plotting this engine. I am not familiar with the original computer system . Would I be limited to particular intake manifolds and the oem carb? Are modifications required to the PROM (programming changes)? Does anyone have any information as what particular IC it is? In the field I work in, I may be able to make these changes myself if anyone can let me know who makes the chip, and what series it is. Unfortunately, the aftermarket/auto-industry has been known to remove the laser etching on the IC, making it very difficult to impossible for people like me to buy a 50 cent IC and programming it to my needs... so it may be a possibility that these IC's are actually "blank" under the label that is usually placed on them.

Tranny: TKO500/600 is what I plan to swap out the T5 for.

Other: I am not well informed on these cars in general. So if you have any additional information/suggestions to what to upgrade to handle the extra power, please let me know. Subframe connectors are definitely on the list of "must-do's" if I can find the car that I'm hunting for.

Thank you all in advance!

 

You are worried about the wrong thing as far as an LS swap goes....I'd be more concerned w/ fitment and trans mating/fitment than looseness of the body. They are all loose. Did Chevy make them to seld destruct w/ more than 250hp? No, they just need buttoned up.

 

Engine and tranny fit shouldn't be much of an issue... I've stumbled upon others using an LS3 and the Tremec Magnum.


Most performance publications have mentioned that structural improvements are essentially a must when going with more power on this generation. It is a valid concern when it comes to the structural integrity of the car.

 

The first question should be what are you planning on doing with the car......racing it with sticky tires or just having a street car with radials?

 

Street with zero intentions for it to see the track.

 

For sure subframe connectors are a must...either bolt or weld. I don't see the difference between a pre-LSx and any LS motor. The question regarding tires was a good one. You'll lose traction with street tires in an instant, slicks /hooking up is when doors don't close anymore.

 

Ok the next couple of things to look at are are you going to lower the car if so how much and what type of exhaust are you thinking of. If you lower the car significantly the possabitity of a dual exhaust with any type of even remotely quite mufflers along with subframe connectors becomes next to impossable....if you stay with street tires the subframe connectors are not necessary

 

Stock ride height. exhaust - catback with a straight thru muffler such as dynomax or magnaflow.

 

In that case you should have no issues with putting in sfc's

 

FYI
Gen1 is Old school SBC 1955 ?
Gen2 is the reverse coolant, Opti'ed LT1 that came out in 1992 Vett
Gen3 LSx. 1997 Vett