Manual trans behind a warm 455.
 

As the title suggests, I want to warm up a 455 I have with some 6X heads and a cam on stock crank/piston assembly and put a stout enough manual behind it without cutting non standard holes in the floor of either my Firebird or my Judge. Which one is most likely to live behind the street engine? As I understand the TKO requires cutting more floor than facotry? I have an M20, a Saginaw and an HD cast iron Muncie 3 spd now. Is the Super T10 the best option? Or should I use a Supercased Muncie? Am I wrong on the TKO fitment?

You will have to cut the tunnel on ther GTO. I know, I did it on my 70. I think you may not have to on the second gen F body. Go to Classic Chevy 5 speed web site. Tons of info and great guy to work with. Highly reccomended. BTW, putting the TKO in my 70 was the best mod I have ever done to any car.

A richmond 5 speed will bolt right up, you just have to run 2.56-3.08 gears. Slight massaging of the floor pan to clear onr shift rod. No cutting. OD trans.

So, the Richmond will be better behind the 455 then? I suppose the massaging could be undone with a little work if so--if wanted.

I won't cut the tunnel on the Judge.

The shifter ends up in a different spot so you can't use the console without mods.

Maybe the HD3speed will live if you don't use a sticky tire.

Pulled from one of my earlier posts:

I have the Tremec TKO600 5-Speed w/.64 overdrive. It is modified by Keisler Engineering and bought from same as a kit. Kit included everything needed
for the swap including new cross member, driveshaft and speedo cable among other things. I installed it in a 1976 Trans Am. There was not one hole drilled and not one cut necessary. It was a direct bolt-in. I could not be happier with my choice!!!
Old set-up was stock 200HP 455 w/ST-10 4-speed and 3.23 rear gears. Best recorded gas mileage w/old set-up was 12mpg (tired engine). New set-up is freshly built 462 w/500HP (estimated), Keisler/Tremec TKO600 5-speed and same 3.23 rear gears. New best recorded gas mileage is 22.6(All Interstate-Non Stop)!!! RPM's at 80 MPH have decreased from 3000 to 2000. Bonus is 1st and 2nd gears in Tremec are lower than same in ST-10. Real reason for making swap is that I did not believe my numbers matching ST-10 would hold up to the power of the new engine. Gas mileage is a sweet bonus!!! Would do it again in a heart beat!!!

Doug,
FWIW, I have an M-21 in my Judge (Street Car) and it lives for over 6 years now. The car has even made countless low 12 sec passes at the strip.

Chris, my buddy with a Muncie in his 70 TA with a 428 broke numerous parts.

Thanks all.
So loggerhead, how long has the trans been in your car?

Skip, I've always felt I was on borrowed time, but I think what saves mine is I don't do High RPM side step launches. My car 60ft's better with a "roll into it lauch" as apposed to a side step launch. I'm sure a few side steppers and I'd have parts on the ground.

Doug, I also installed a TKO-600 in my 76 T/A. I got it from Keisler as well and the "Perfect Fit" kit was exactly that, a perfect fit. I didn't have to massage or cut anything. I know that won't be true for your GTO, but it will be for your Firebird. I've only got about 600 miles on it as of now, and they are break in miles at that, but if I had it to do over again, I wouldn't change a thing. You will have a tough time breaking a TKO-600 with a warmed over 455. Oh, I'm also running a Moser 12 bolt with 3.73's.

I beat the holy hell out of a freshly rebuilt M22 with my Bisschop motor, it took 4 years of spirited street driving. I have laid down about 40 12 second passes and many, many mulitple gear burnouts.

I bent the tailshaft and wasted the Italian gears ! Plus 3 clutches. LOL :knock:

Last year I put a really nice custom made Supercase M22 with the 2.52 first gear ratio in my 70 Judge. It also has that beefy gusseted tailhousing.

It's holding up just fine.

It's not easy being dedicated to 4 speeds but they sure are fun to drive :D

I would keep the judge stock w/ the HD3speed...put the keisler in the TA for your fun OD cruise. OTOH, Richmonds can be had cheap and they are pretty strong. Mine survived on slicks and sidestep launches to 12.10's at 112mph more than a few times. No cut in A body, best of luck in whatever you decide.

Once you put an OD trans into your musclecar you will NEVER want to go back to 4.10-3.90 even 3.55's can be a little steep when you get used to 2.56's....

Doug,
One option with Keisler is they are right down the road from you in Rockford. I used to work with the owner about 10 years ago before he went full time into the conversions. It will not fit in the Judge without cutting the floor but may fit in your Firebird.

Here's what happens to a ST-10 with 500+ HP connected to it. Split case and wasted gearset. Don't use sticky tires if you want it to live. My choice would be a Supercase M22 from Gearzone or the TKO-600.

HaHa, You got that right Larry, I'm going to take my M/T Drag radials off in about an hour and put my regular BF Goodrich Comp T/As on.

Two years. No Problems. You can do a search and find more about my experience.
Be glad to answer any questions.

David

You can thrash and trash any of them, if the tranny don't break, something else will.
If you are planning on breaking something, you need to HD the whole drive train, from flywheel to lugnuts.
In my younger days, "I" broke more than my fair share of 3 & 4 speeds. I can't fault the transmissions, it was the "I" behind the wheel.
I like the T-10s, you can play with them as hard as you like, as long as you don't abuse it. As long as you don't yank one with slack in it, they will probably all stay together.

Very true! When I was planning my project I quickly realized that as I progressed I was simply moving the weak spot further down the driveline. It started with the billet flywheel and HD clutch, scattershield and TKO-600. Keisler provided the custom driveshaft with HD yolk and U-joints. Then came the Moser 12 bolt with a 1350 yolk, Detroit Tru-trac posi carrier and 36 spline axles. I think my drive train will survive whatever I can throw at it at this point.

Thanks all for the good information--and I didn't know there was a place called Keisler that is so close and that they sell a kit complete. Good info. But it sounds like I'm going to need some overtime pay for the rest of the mods. :burnout: