4speed Vs. 3500

[ericjon262]

would a fiero 4 speed manual hold up to a 3500? if not, does the shifter and clutch mechanisms off of the 4 speed work on the F40?

Thanks-

Eric

[Emc209i]

Yes, the 4 speed would be ok behind the 3500 - no idea about the crossover pipe hitting the cable bracket like it does with the 3800s. No.

Eric, friend of mine has a 3500 powered Impala that's already blowing black smoke out the exhaust at 65,000 miles (purchased new, female driver). The 3400 was a completely foul rigged engine, the 3500 doesn't seem to offer much promise either. I'm completely for being different and the cool factor of the 60*V6, but if I had a close friend considering the swap, I'd talk him out of it. There just isn't enough positive to be had in its corner. :\

[The Dark Side of Will]

If you have the V6 four speed with the extra ribbing on the case, you'll be fine.

If you have the 4 cyl four speed with the smooth case, you may have to take it easy.

[ericjon262]

so I need to check for ribs on the trans case, is it a huge difference between the two?

as far as the 3500 is concerned, there's a guy running around near me with a turbo 3500 that hauls ass, and I have a few of my own little things I want to try with the 3500, if it goes boom, well then I'm out $250.

[Emc209i]

Fair enough.

[Atilla the Fun]

The 4-speed shifter is the one to start with if you do go F40

[ericjon262]

I should be going to get the 4 speed on Saturday, that and a few other goodies, hopefully I can get the car going strong again. my new truck isn't exactly gas friendly.

[Atilla the Fun]

tell us more about your truck. trans, axle, tires, lifted or lowered, mods, et cetera.

[ericjon262]

when I said new, I meant new to me
it's an 1987 Chevy R30 (1 ton rear wheel drive) L19 454 (TBI) Bonus cab, Turbo 400, 8' bed, dually with a corp. 14 bolt (4:11) it's got longtubes, and it'll have an EBL Flash board from dynamicefi.com sometime next week. other than that it's bone stock...I think. I don't have much planned for it until I get my house built (and workshop ) and my Camaro and Fiero "finished"

after that I'm debating on whether I'll lower it, or convert it to a 4x4. I'd like to swap a Vortec 8100 into it, or a duramax, either way it would be bad! but it'll be a while before I get to that.

[Atilla the Fun]

454 and 4.10:1 ( not 4.11 ) with no overdrive and no lockup explains your fuel consumption. You can't really blame the Q-Jet, because those can run leaner than EFI. Plus that lame 2.481818:1 first gear ratio...
You did well to find a 2WD version. Around here, they straight don't exist. At any price. Plenty of 6WD versions, however.

[ericjon262]

I ment 4.10 either way, it wasn't built for gas mileage. I'd like to see how much it weighs on a scale, o wouldn't doubt it if it was over 5500 pounds.

[Atilla the Fun]

It better be. My '06 Sierra 1500 4.3 is over 4500, with an aluminum driveshaft, a standard cab, and single rear wheels. Though it must be admitted, I do have heavier brakes.

[ericjon262]

yeah, the brakes are alright on mine, but I would prefer something with a little more grab, hopefully they're just a little worn, I plan to do a thorough inspection of the frontend sometime later this week.

[Atilla the Fun]

On the rear, you have some options. But up front, the best you can do is metallic pads, braided stainless hoses, and shorter tires. There are NO big brake kits for those, nor any bolt-together caliper upgrade kits. Adapting later stuff would be new territory, but you could do larger rotors and multi-piston calipers. More pistons = more clamp from any given line pressure. Some of the newest duallies need ( and come with ) 17" wheels, just to clear the bigger brakes. In the rear, you can get a later axle with stock rear discs. Big money to do everything necessary, but it can be done. I just swapped my '06 Sierra from the 10-bolt with drums to an AAM 10.5" 14-bolt full floater with stock rear discs.

[ericjon262]

anything is possible, just depends on how in depth i decide to get with it. right now though, it's almost at the very bottom of my mod list.I already have too many projects, so I shouldn't turn my truck into one quite yet.

Does anyone know If I'll need new axles for the 4 speed swap?

[Atilla the Fun]

Are you swapping from a TH125c?
The ribbed-case 4 speed takes the same axles as the smooth-case versions, but aside from the case, the ribbed version also got stronger first and second gears. First is 3.31:1 and second is 1.9500:1 in the strong version, versus 3.53:1 and 1.9545454:1 in the weak version. The strong one used a 0.81:1 fourth with a 3.6522:1 final, which is no stronger than the alternatives. The rare '84 econo used a 0.73:1 fourth, with a 3.32:1 final, and the '84 sport used the 0.81:1 fourth, with a 4.095:1 final. All used a 1.24:1 third. First and second must be changed together, third and fourth must be changed together. But you can use either fourth and any final in the ribbed case. Until the F40-MT2, the ribbed case, with the stronger first and second, but with the econo fourth and final, was THE combo for V8 guys wanting low cruise rpm.

[ericjon262]

Yeah, I'm swapping from a 125c.

[ericjon262]

I finally have the transmission and related components! now for the fun part, the swap! I only have one question,


will the axles from the auto trans fit the four speed?

[Shaun41178(2)]

I want to say the drivers will, but you will need to get a new passenger axle

[ericjon262]

I have the passenger side axle already, so thats would be awesome is thats the case.