Thread: 1965 Biscayne/5 speed conversion

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I am restoring a old drag car(65 Biscayne) & drove it for the first time a few days ago.

I am pleased with the car (350/muncie/lowered 4"/59 dash/T-bird buckets/Z-28 steering box) with the exception of the Muncie M-20.

I would like to reduce the highway RPM's, but do not want a auto trans. I also have out lived my retirement savings so money is critical.

I must admit I have not kept up with 5 speed trans.....what are my options.

Hi to all my old friends.

Don

Nice looking car Don.Like the two poster lift too. The T5's are a weak tranny.So is the NW series.Actually they are worst than the T5's. The stock based tranny(not aftermarket) to get would be a T56 which is a 6 speed.

http://www.chevyhiperformance.com/te...smission_swap/

http://en.wikipedia.org/wiki/Borg-Wa...6_transmission

This a copy of a Ebay add of a company that does work on T56's and it seems they need alot of work to get them to work correctly. Here is the ad:



Transmissions are completely disassembled, de-greased, all parts carefully inspected. Rebuilt using performance upgraded parts, with severe use in mind!


Performance parts list:

Upgraded 1-6 carbon fiber/kevlar blocker / synchronizer rings
Reverse synchronizer ring
Bronze fork pads for the 1-2 & 3-4
Billet keys for the 3-4 with upgraded springs
Billet keys for the 1-2 with upgraded springs
Bronze shifter bushing / isolator cup
Snap ring kit
3-4 steel shift fork
Stock 5-6 & reverse fork pads
Stock 5-6 & reverse keys & springs
front & rear seals


·Carbon fiber/kevlar blocker / synchronizer rings
Carbon fiber/kevlar blocker / synchronizer rings provide much better shifting than stock paper lined parts.
·Bronze fork pads 1-2 and 3-4
Bronze fork pads are a necessary upgrade for all T56 high performance and racing applications! These will not fail or wear like the stock Teflon pads.
·Billet Synchronizer Keys 1-2 and 3-4
Billet keys are a necessary upgrade for high performance and race applications. Replace the weak stamped steel keys with a superior billet material.
·Steel 3-4 shift fork.
This is the upgraded T56 3-4 steel shift fork used in the Vipers and will fits all T56 transmissions. It replaces the weaker aluminum shift fork with a much stronger steel fork.

And then from a end user:

Do you have a Gen I or Gen III/IV engine?

If Gen I, you can use a stock LT1 T56, flywheel, and hydraulics with no issue as long as you have a 1 pc RMS engine. The 2 pc RMS engines require a $400ish conversion flywheel. The 93 T56's had slightly shorter gears all around and were rated for less torque. Generally the concensus is to avoid them.

If Gen III/IV, the LS1 F-body T56 is the ticket. All 94-02 F-body T56's had the same gear ratios as far as I am aware.

You can convert a 98-02 F-body T56 to work with a Gen I engine but it requires an adapter plate at least, maybe other issues too. A 94-97 T56 costs around $600-$1000 for parts to convert it for use with a Gen III/IV engine down the road. That may affect your decision.

The LT1 T56 uses a strange clutch with a reverse-pointed slave cylinder. They're fairly unique and there arent many clutch options out there. There are enough, but aside from maybe the high end Mcleods, they all use the exact same Valeo pressure plates. They increase grip by changing the clutch disc material, not by increasing clamping force. Normally this isnt a big deal, but its a transmission they only made for 5 years, you're just not gonna have a TON of options on it. But there is enough available that it isnt a huge concern. the clutches do cost a little more though it seems. $250 is about the starting point.

The LS1 T56's seemed to have crappy hydraulics from the factory. I think i read that GM didnt allow full pressure to the slave cylinder, so you never got complete clutch disengagement... something weird like that? Hence things like the "drill mod". LS1 T56's seem to go through synchros a lot faster, but that could be because of crappy hydraulics or because LS1's make oodles and caboodles of power. Nothing a fancy aftermarket $300 Tick master cylinder cant fix. The LT1 T56's despite being older and more worn out seem to last just as long, but they are getting very old now.

CTS-V and GTO T56's can work, but they require a lot of conversions to get them into other vehicles. The F-body ones are a direct drop in. If this is for a non F-body, then it may not matter so much. Corvette T56's are integrated into the rear axle and IRS, so they pretty much only work in corvettes.

I have a T56 from a 94 TA that was bracket raced and power shifted hard. I learned how to drive a stick with it in my car, and the thing makes noises, but it's held up great over the years Ive had it. They're very tough transmissions, and I think everything from 94+ had at least a 450 ft lb rating.

As it always is,there is a substantial investment to have something that will last.

Don,
You might consider a GearVendors Overdrive unit behind that Muncie as an alternative - here's a link to the one they push for your application Gear Vendors under/overdrive auxiliary transmissions Hot Rods, GM 4, 5 and 6-Speed Manual Muscle Car/Street Rod/Sport Truck.
I was totally unfamiliar with them until Dave Severson posted his thoughts about using one in his '57 Chevy project, but after doing some reading they seem to be a very viable alternative - not cheap, but a good option. Good luck on your search.

I forgot to mention that my engine is a 1972 350....Don

The Gearvendors came to light on a RV web site. What the general concision was it would take a long time to get back the investment in gas mileage given the costs of the unit. I wanted to add that a engine's power(the ones on the lower end of it) might eat more gas trying to power the o/d. I would guess your car isn't too light wt.

Well Gary, you once again reinforced why I pulled back from posting here, and why I'll pull back even farther now. Seems that no matter what I post you re-post trying to discredit what I've said. GearVendors has different products for different applications, from big trucks to RV's to hot rods, with each dialed in for the intended use. I'm pretty sure that Dave pointed out the losses that the units impose in his thread, and they were minuscule because of their design. As far as the general "consensus" in an RV magazine??

Don, best of luck with your modifications. I'm glad to see you back, and I really think if you read about the GearVendor unit it might be a good fit for you if the cost is not too much to handle, especially if you could find a used unit out there somewhere - maybe one of those RV guys that thinks they aren't any good has one cheap!!

Bye guys & gals. You may see me lurking once in a while, but it'll be a while before you see my avatar again.

Roger don't let that know it all clown run you off nobody pays attention to him just ignore him I for one enjoy your posts and I don't think I am the only one .....ted

Don
Maybe I missed something , but what rear end gear ratio are you running now ?

I'm looking at a Gear Vendors OD for my sons car. I'm sold on them. For me, the gas savings would be a moot point for the addition. I don't know how much money you guys have in your engines, but I know what it will cost to replace my sons stroker. I fear the engine killer.......high RPMs. Sure we could drop in a modified tranny, or different gears. But my ex wife always said I was a complicated individual.

David

I am running a 3.23 rear....I might also mention that my disappointment with the Muncie is also the way it shifts.
I am used to a silky smooth Z06.

What trans did the 5 spd 90's(?) camaro use with a 305?
Would that not work?

Don

Don

Don. It's great to see you back. Like you I haven't really kept up to much with the manual overdrives. I do look up some specs on them from time to time.

From what I've seen though, you really have to watch the T5s and 6 speed T56s as far as the application they came from. The torque rating varies a lot between the different applications. There are several several listings that come up when you google Troque rating T5 or T56 that should help.

The gear vendor is also a decent option, but doesn't address the shifting of the Muncie.

Thanks Mike, I have had serious health problems & they are still continuing. I am scheduled for
a cath Fri & possibly a valve replacement.

Thanks Don

Good luck to you Don. Ain't it a shame they can't rebuild us like we do with our cars.

.

Don,
Keep your chin up. I'm still moving around with three stents.

The T5's where in use behind the 305's. History has proven they are a very weak trans. We had a guy on a Astro/Safari site do a world class update to one to use behind a swapped in 383. Major money and still at times didn't shift as it should.