Putting a manual behind a SBC - Cheaply

I know this has been discussed before, but within a challenge-style budget, what are my options for swapping a manual into an automatic F body with a 305 and plans for a 350 at some point?

It looks like the going local price for a working T56 on CL or car-parts.com is about $1500++. On the other hand, a rebuilt Muncie 4 speed with no core is about $1300, used with no warranty is still $800. Surely there must be other options. I think a T-5 would be ok with the wheezy 305, but not when/if we drop in a 350/383. Are those T-5Z’s any better? What about manuals from trucks? I hear that they don’t have the right ratios, but how bad are they really?

Any other off the wall junkyard sourced suggestions? Mark III Supra? BMW 540?? Jaguar XK8??? It seems that considering how common SBC’s are someone must have come up with a cheap alternative transmission that would work.

SM465 :)

Having owned a 5 speed camaro with a stock LG4 (low-output 305) and an unknown-but-probably-stock 350...a T5 was just fine for me. I've got the mechanical sympathy and was confident I could have made the transmission live. Even with quite a bit more power, it would be ok if driven as if the T5 is the weak link. Note...that doesn't mean you can't race...just be aware.

The cheapest option is likely going to be a stock T10 (4 speed) that came in the '82. it'll already have the bosses on the tail housing for the third link on the rear suspension. If you get on thirdgen.org or similar and find someone who's upgrading for more gears, you might be able to get one for significantly less then the other options you've listed above.

Something to consider as well is that '82 and '83 F-bodies had a Z-bar type mechanical clutch release linkage. '84-up had a hydraulic clutch. I converted my '83 to hydraulic with used parts from a later car.

Here's a run down on tranmissions and stuff for jeeps. http://www.novak-adapt.com/knowledge/gm_generation_III_v8.htm I like their website and use it often. Though I've never purchased anything.

the new venture box from the v6 s10's? I know mine put up with a lot of punishment from the 4.3+spray

no need to reinvent the wheel here.. just find someone selling off the T5 and all the supporting parts from a V8 F body- try to get one from a later 3rd gen because it will be the World Class box that was similar to the one used in 5.0 Mustangs. if you add power later, you can upgrade the trans to take some abuse with less dollars than it would take to buy a used and thrashed T56.

Thanks to everyone who has replied so far.

Clem - I neglected to mention that this is a 2nd gen, a 78 Firebird Esprit. This car was built and sold in CA and came with a Chevy 305.

Derrik - I tend to agree with you on the T-5. But you wouldn't believe how many internet "experts" swear up and down that it just won't hold up. Funny thing is thousands of them are working just fine in Mustangs of all sorts, some with a lot more power than this Firebird will ever see.

Id get an NP435 before an SM465, at least they have 4 useable gears.

If you can stand a 4 speed, I'd look at the Super T-10. I've seen them for sale for a few hundred bucks in working condition and they're supposed to be at least as robust as the Muncie. The earlier T-10s aren't supposed to be as strong.

rumor had it a vega 4 spd would hold up behind a small block-never tested, often heard. Now anybody got some USEFUL info?

Which gen of F-body? I am ASSuming 4th gen with the mention of a T56. I believe I would be using the "Fair" formula to Challenge building. The formula was the bellhousing was "free", so you need to find what trans you would like to run and go from there.

Look for 80s chevy half tons with overdrive 4 speeds, it will likely need bearings, as it is actually based on the old mopar 4 speed with an overdrive gear in the 3rd position and the 3/4 shift rod flipped(so the lay shaft is transmitting power in top gear). My dad beat one relentlessly for 3 years in his 84 C15 DD/wood hauler with a 350 2 barrel. He ended up going automatic because he was so hard on the truck it ate a clutch every year, and needed bearings by the time the 3rd clutch smoked.

I have a vega 4spd that will be tested behind a 350hp LR4 . . . 3.11 first gear I believe . . . I got it for $150.

Here's the info I have:

Saginaw 4 Speed: All cast iron, No separator plate between front case and tail housing. All shift levers (3) in the side cover. 7 bolt side cover. Lowest rotational weight.

• No lines on the input shaft 1st-2.84 2nd-2.01 3rd-1.35 4th-1.00
• 1 line on the input shaft 1st-2.54 2nd-1.80 3rd-1.44 4th-1.00
• 2 lines on the input shaft 1st-3.11 2nd-2.20 3rd-1.47 4th-1.00
• 3 lines on the input shaft 1st-3.50 2nd-2.47 3rd-1.65 4th-1.00

Second Design Borg-Warner Super T-10: 9 Bolt side cover. May be all aluminum, all cast iron, or half and half

• 2 lines on the input shaft 1st-2.43 2nd-1.61 3rd-1.23 4th-1.00
• 3 lines on the input shaft 1st-2.64 2nd-1.75 3rd-1.33 4th-1.00
• 5 lines on the input shaft 1st-3.42 2nd-2.28 3rd-1.46 4th-1.00
• 6 lines on the input shaft 1st-2.88 2nd-1.91 3rd-1.33 4th-1.00

Truck transmissions will have the shifter too far forward for the Firebird (think shifter almost under the dash). The T5 will work if you don't abuse it. A Super T10 would be a good choice, with some patience you can find one for a good deal.

Didnt the Vorslag E30 pop multiple T5's behind thier 5.3? I dont think they actually made a full pass in either challenge they ran in before breaking 3rd gear.

I run a t5 in my 240sx behind my lt1 which puts down 375hp to ground. Has been 7yrs of abuse still together even survived a exploded rear universal joint.

TH350 + manual valvebody + ratcheting shifter.

Pat wrote: Didnt the Vorslag E30 pop multiple T5's behind thier 5.3? I dont think they actually made a full pass in either challenge they ran in before breaking 3rd gear.

They also used the even-more-worthless-then-the-Ford 4cyl T5, Camaro T5.

the manual valvebody th350 plus ratchet shifter is pretty nice - no clutch.

3 Speed!! You can get a complete 3 speed Saginaw set up for $300 at the most, and they are strong enough to be the bread and butter of pure stock, street stock, and open wheel modified racing all across this country.

Now, most people will scoff at the idea of a 3 speed, but in a GRM Challenge car used for autocross and drag racing, how the hell can you justify a 5 speed when you'll almost never get a 5 speed out of 2nd gear, anyway

Kenny_McCormic wrote: Look for 80s chevy half tons with overdrive 4 speeds, it will likely need bearings, as it is actually based on the old mopar 4 speed with an overdrive gear in the 3rd position and the 3/4 shift rod flipped(so the lay shaft is transmitting power in top gear). My dad beat one relentlessly for 3 years in his 84 C15 DD/wood hauler with a 350 2 barrel. He ended up going automatic because he was so hard on the truck it ate a clutch every year, and needed bearings by the time the 3rd clutch smoked.

I have, and have driven this tranny behind a small block. I love it.

tuna55 wrote:

Kenny_McCormic wrote: Look for 80s chevy half tons with overdrive 4 speeds, it will likely need bearings, as it is actually based on the old mopar 4 speed with an overdrive gear in the 3rd position and the 3/4 shift rod flipped(so the lay shaft is transmitting power in top gear). My dad beat one relentlessly for 3 years in his 84 C15 DD/wood hauler with a 350 2 barrel. He ended up going automatic because he was so hard on the truck it ate a clutch every year, and needed bearings by the time the 3rd clutch smoked.

I have, and have driven this tranny behind a small block. I love it.

This has my interest piqued. It's the first I've heard of this transmission. What's the name/designation of it? Sounds like a good way to put an overdrive in a truck or other old non-hotrod cruiser. Just looking for search engine entry fodder so I can study up on them.

Thanks!
Clem

Ranger50 wrote:

Pat wrote: Didnt the Vorslag E30 pop multiple T5's behind thier 5.3? I dont think they actually made a full pass in either challenge they ran in before breaking 3rd gear.

They also used the even-more-worthless-then-the-Ford 4cyl T5, Camaro T5.

Didnt realize that there were so many variations of the T5.

ClemSparks wrote:

tuna55 wrote:

Kenny_McCormic wrote: Look for 80s chevy half tons with overdrive 4 speeds, it will likely need bearings, as it is actually based on the old mopar 4 speed with an overdrive gear in the 3rd position and the 3/4 shift rod flipped(so the lay shaft is transmitting power in top gear). My dad beat one relentlessly for 3 years in his 84 C15 DD/wood hauler with a 350 2 barrel. He ended up going automatic because he was so hard on the truck it ate a clutch every year, and needed bearings by the time the 3rd clutch smoked.

I have, and have driven this tranny behind a small block. I love it.

This has my interest piqued. It's the first I've heard of this transmission. What's the name/designation of it? Sounds like a good way to put an overdrive in a truck or other old non-hotrod cruiser. Just looking for search engine entry fodder so I can study up on them. Thanks! Clem

it's the Mopar A833 overdrive manual trans with a GM input and output shafts on it... the early cast iron ones require a special bellhousing due to using the mopar bellhousing flange, but the later aluminum ones will bolt to any 80's GM truck bellhousing.

I think you can adapt the Ford RUG 4-speed with overdrive to a Chevy bell housing as well without a lot of work, from a half-ton early 80's pickup. Gears are a bit wide, but not undrivable.

Also might want to look for a corvette 4+3. They are plenty inexpensive.

The Supra or Toyota pickup 5-speed units are a cost compelling option, especially if space is a consideration. Their bodies are so narrow. Any of the 4x5 truck places sells adapter bell housings, and you'll have to wade through the alphabet soup of tranny names to find a version you like with respect to ratios and availability.

And the later S10s have an integral bell-housing on them and you don't hear of them failing nearly as often as the older T5s. I'm going to run one behind a 4.8L in my S10 and have no worries.