I just cannot get the thought of an AFM 5.3 (or bigger, but the AFM is the key) in 3rd gen Firebird or Trans-Am. Basically I want something that can haul ***, runs good on the cheap stuff, and I can achieve 30mpg+ on the highway (when I can keep my foot out of the throttle, at least ).

I am wondering if there have been any build threads, or if there is any info specifically on the AFM engines? I tried to search, but... the title.

Also, I love manual transmissions, but I have yet to see a vehicle with both manual trans AND AFM. Is AFM dependent upon an auto trans? If so then there goes my manual trans idea, but so be it.

 

Welcome aboard thirdgen.org.

It isn't very well supported by the aftermarket, and most people doing an LS swap in a 3rd gen are more interested in performance than in economy.

The factory didn't used AFM on manual transmission cars because it tends to be jerky. I believe they have started using it with the new LT1 in Vettes, but not sure if that's still only auto trans cars, or both.

V8rumble is planning on using the L76 system with a T56, but he's still working through the swap details. Not sure if he's found a tuner to work with, either.

 

Shutting off half the cylinders isn't necessary to get 30 MPG, the Z28 was doing 30+ back in '98.
It'd be easier to get there with a 4.8 than a 6.2, then a turbo would more than make up the HP difference. Which is what I'm doing if I can avoid having to sell my '86 to pay for the running '94 I just got.
T56s are way overpriced when you can find one, the T5 isn't strong enough, and nothing else bolts in for less than twice the price of a used T56.
In my case, I got an insanely good price on a new set of GM 50# injectors, which are good to 580 HP. That, plus I don't like the way the poorly-geared 4L80E drives, means I'm planning on needing to invest in some upgrades for my 4L60E. Plus the 4L80E requires butchery, and the 6Ls require even more.

 

I get 26 mpg with my 5.3 + 4L60E swap, could be better if I drove like a saint

 

Who says saints don't speed? Anyway, you could get there by swapping your 3.27:1 gears for 2.77:1. It's all over LS1Tech.com, and has been for years, how the LS1 doesn't care which axle ratio you have once you buy a Yank or similar torque converter then get it tuned.