Thanks so much for this forum, I’ve learned a lot! I have an 84 SE that was a 4 cyl with the Muncie 4 speed (MM4) 4.10 ratio (FW5). I bought and installed a 77 sbc 350 with the Archie kit. Obviously, lot of power and not a lot of gearing. I was curious about suggestions for a transmission upgrade. I see a lot of buzz on here about f40 (and it’s costs) and also f23 (not as much talk).
I’m not a crazy hard driver, will be using the car seasonally (New England) and likely not doing a whole lot of highway driving unless going to shows. I’ve read on here some people really favor the four speed but it just seems to reduce the value of the engine I put in. Which of the transmissions suits me better? Also, regarding the f40, I’ve heard the later ones are better. I see some on eBay but have no way of telling them apart from others I see on there. Are there numbers or models to go by that are better? Or manufacture years? Or is the f23 sufficient with the fifth gear? Is that able to mount up to my 350?
Sorry so many questions but I didn’t see a thread that dealt with my specific application. Thanks in advance for any direction or advice! Dennis F in MA

Well the first step is to choose what ratios you want.

Then, you compare your wishlist with what's out there and within your budget.

What is done to your 350? What vehicle did it come out of?

Just having an SBC doesn't say much about its power output or torque curve. Those along with intended use will determine your optimal gearing.

The easiest swap would be to upgrade from the 4.10 to the 3.65 4 speed. It would be a direct swap, no additional parts needed, and give you better gearing.

Swapping to the Getrag 5 speed (fiero version or the 92-94 HTOB) would work as well, but you will need the transmission mounts, shift & select cables, some minor changes to the reverse switch, vss (depending on year of getrag) and swap to a getrag throw-out bearing.

F23: if you keep the stock final drive, it will feel a lot like your 4.10 4 speed with a 5th gear. Mounts, cables, custom shift bracket, different clutch setup, etc.

F40: not for the cheap, but is a strong and versatile transmission in stock form. Needs mounts, flywheel, clutch, custom shifter bracket, custom cables, custom axles, etc.

F40 with 3.09 final drive swap... AWESOME, but add another $2,500+ to the already expensive F40 swap.

The F23 that bolts up has a 0.69 top gear, but a 3.94 axle ratio. It uses the same CV axles as your current Muncie.

You can build one F23 from two and end up with a 3.63 axle ratio. This box has almost exactly the same ratios as the original Getrag 5 speed.

The 2006 Pontiac G6 F40 (Option MT2) has 0.62 top gear and 3.55 axle ratio... it'll give you much more relaxed cruising RPM, but more expensive to buy and install.

You could swap in a Getrag 5 speed using all stock-type parts and it'll probably be fine as long as you don't drive like you're 17.

Thanks for the prompt responses! I’m going to have to do more homework, it sounds like. I don’t know a lot about the f23 and f40 or what they came in. Would love to find one around here.

I'm outside of Worcester and maybe right in your backyard.

My first V8 swap was in 1999 with an 88 GT. At that time I used the original Getrag 5 speed and drove it for 8 years, around 28K miles, with no issues at all. I drove it everywhere but, like you, limited in New England winter.

The same car now has a different motor and an F40 6 speed. This current rebuild of the car began in 2015 and I'm finally wrapping up the last details and have begun to drive it. The reason for the F40 was mainly that the Getrag had around 140K on it and I knew this was going to be the last time I wanted to have the motor out of the car. Plus, I had enough budget to buy a new F40 from a member in Florida.

I think these cars are a lot of fun with any stick shift.

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88GT 355 CI Sequential Holley HP Multiport EFI, AFR milled 180, Dyno'd at 427 HP, 320 WHP, F40 6-Spd
anderson@gdsconsulting.com

Hey, Steve! Yeah, I spoke to you when I was first beginning my conversion. I believe Archie put me in touch with you. I’m in Milford so not too far away at all. Sounds like for ease and budget I’d probably start looking for a Getrag or even the better geared 4speed. I just want to drive it! Been 3 1/2 years of the work without the joys. Dennis F

I have the 86 4 speed on my car, it works well, the only downside is freeway driving, but only if you want to drive at 80, if you tottle along at 65 ish its fine. And then when you stomp on it hold on, it takes off, no need to change down. Again depends what you use the car for, for me its a fun toy to clear out the cobwebs.

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84SE, aero body, 4 speed and an injected 355 V8