Transmission Advice

[LDO]

Ok gang,

need a little advice here. I have a 66 c10. Had a 283 with a Saginaw 4 speed in it.

Pulled 283 and will be installing a 290HP Crate 350.

Saginaw is tired so I'm looking for a new manual gear box.

REALLY wanted a TKO 5 speed but my budget is telling me I may want to look at other (cheaper) options with all the other 'stuff' I would like to do to the truck.

Truck has 3.08 gears so I'm not sure that I would see too much of an advantage in going to a 5 speed (TKO 500) unless I swap out the rear end gears (more $$).

Not against a Muncie 4 speed but all the #s and gear ratios can be a little confusing.

Am I going to need to swap out rear gears with that too?

Tires are 29 inches tall.

I want the truck to be fun to drive in town (not a dog) but still be able to handle highway speeds without high rpms.

Am I being realistic?

Thank you in advance for your help.

[corvettejim1968]

I can tell you 3:73 is a great all around gear ratio.

[patrickk1]

You could do a Built ax15 from a Jeep. Built, they handle about 400hp and you can buy a built one for $1200 (or just buy a junkyard one from craigslist). You would need a chevy to ax15 adapter. Has a steeper 1st gear and not as much of an overdrive (3.83 first, .79 overdrive). That should give you a steeper 1st overall than you have now and also 5th gear at 70mph would be around 2000rpm without changing your rear.

[chevyrestoguy]

Since you're not making a ton of horsepower, why not a T-5? They produced literally millions of those things, and there are a bunch of 3rd and 4th Gen Camaros in the wrecking yards for parts.

They are a pretty good transmission as long as you don't abuse them.

[Lugnutz65]

A Muncie T10 is the 4 speed of choice for many folks with the 3.08 rear. Nothing wrong with it and no adapter plate needed. If you want more pep at the light then changing the rear to a 3.73 or 3.42 is going to do that but then the highway RPMs will not be as favorable unless you install an OD tranny. I am a fan of the Borg Warner T5 and have one in my 1965 C10 with a 3.73 rear. Any T5 can be bolted to your SBC V8 or 230 250 292 L6 without using an adapter plate as long as the bell and T5 both have a Muncie pattern. The T5 has lots of different versions and gear combinations.
Rather than ramble on . . . . Let me just say you could install a T5, shorten the drive shaft, keep your same clutch package and drive it. If 5th gear was too high in combination with your 3.08 diff, then you could swap rears later. Meanwhile you would just use 4 gears until you swapped rears. My website has tons of info on the T5. Take a look.

[patrickk1]

If your going to install a t5, Id recommend you at least install a billet cluster support plate. There only $40-$50. The factory stamped steel ones flex under hard deceleration and cause the countershaft to become out of shim and get excessive end play in it. Once the main shaft gets play in it over time the two will eventually catch eachother the wrong way and sheer geers off usually 3rd gear.

[Lugnutz65]

The billet plate would only be for a World Class T5. Those would be 1993 S10/S15/Sonoma truck T5s and the 1988-92 Camaro/Firebird T5s.