trans upgrade

[fryedaddy]

if i were to swap out my toploader on my 428 comet to a more modern trans,are there a bolts right up application,if so what.

[475fetoploader]

I was looking at complete kits on American Powertrain just yesterday.  They seem to have nice looking kits, I specifically was looking at Tremec TKX.  I think the TKX has a good chance of being installed without modification to the trans tunnel.  There’s 3 overdrive options as I recall.  I tried calling there tech line 4 times, it was always busy, so not sure what’s happening with that. 

[hwoods]

Lenco ST 1200 I believe has a top loader bolt pattern option.  I have been looking into that

[428kidd]

I guess my question would be why? Are you driving it alot? Interstate driving? Wanting something for a race application? Me id weight what i wanted to do with how much im actually driving it and where.

[Rory428]

Lenco ST 1200 I believe has a top loader bolt pattern option.  I have been looking into that

A racing buddy has a Lenco ST1200 in his 67 Fairlane, which is hardly "a bolts right up" swap like the OP wants. The transmission is at least twice as long as a Toploader, so the factory transmission tunnel required major surgery, not to mention the Lenco is basically a clutchless planetary drag race trans, and obviously no overdrive, which I assume the OP wants.Other than wanting an overdrive, I can`t imagine any other reason he would want to change from the Toploader.

[bsprowl]

I'm starting to build a low 9 second maybe high 8 second '70 Maverick weighing under 2800 pounds maybe only 2500 pounds, hopefully 7-800 horsepower or more with big sticky tires.

I've been concerned about the toploader being the weakest link.  Jerico was on my list as a possible upgrade but they have been having support issues; their older models are no longer supported, read somewhere that they may be gone completely soon.

Treme and Lenco's are real expensive and each bring a whole set of learning curves. 

What other options do we have?

[Rory428]

G Force. I ran Jericos for about 20 years, and did hurt them occasionally  (3 times with 2 different Jerico DR4s, in 2 different cars, not to bad, I think), but was very happy with the Jericos. That was until I broke a mainshaft in the transmission in the Fairmont. When I called Jerico to order a new mainshaft, they told me that they were no longer making parts for the older DR4s, and suggested that I move up to their newer (and much more expensive) DR4-4 version. Luckily I was able to get a used mainshaft from a racing buddy, but not being impressed with Jerico turning their backs on hundreds, if not thousands of racers that had their transmissions, I decided to sell both my Jericos, and bought a nearly new G Force G101A 4 speed. The G Force is a bit taller than the Jerico, and isn`t as "universal"  in fitment, but this will be the 7th year of racing with the G Force, with hundreds of 6000+ RPM clutch dumps, and all that I have done to the transmission is to change the transmission fluid twice. I have been to the G Force factory in Pennsylvania twice, and had the owner, Leonard Long  give me a shop tour both times, it is a very clean and impressive facility, and in addition to the G101A 4 speed that I use, they also offer several higher end 5 speeds. Leonard races a 7 second Mustang in NMCA, using one of his clutchless 5 speeds, so he is a racer that races what he sells. So, I would certainly look at the multiple choices that G Force offers.

[gregb]

What are you wanting in a modern trans, 5 speed with overdrive?  Nothing is going to be bolt in per se, lots of changes will be required.  Me personally would go with a TKX,  2.87 first and .68 overdrive.  If your cam is rowdy and it doesn't like lugging along at 1800 or so you'll want 3.91 or 4.11's in the axle.  Otherwise 3.50 would be the tallest set I would use.    I wouldn't put the 4 speed back in my Mustang for anything after having the 5 speed in there......but, you will need a new clutch disc, a spacer adapter for the trans to bellhousing, new driveshaft, not sure how much you can move the crossmember around on the Comet chassis but it will need to be moved back, also not sure if you will have to cut the tunnel, or modify the piece on the floor where the shifter comes through, although you can buy the shifter tunnel hump new and cut away.....driveshaft will need to be shortened.  American Powertrain and Modern Driveling both offer kits, but I think you are better off sourcing a lot of the stuff separately and getting just the stuff you want.

[bsprowl]

This strictly a drag strip car.  I discovered that there is no class that it fits into since I'm running a tunnel ram and twin 850s so I'll be in whatever E.T. class my weight (2500 to 2800 pounds) and 482 cuibic inches determine. 

The '70 Maverick was certified to 8.5 second by NHRA in 2019; straight axle; fire wall and floor clear to the rear are aluminum; windsheild is plexiglass; gas tank is gone.

I have a TKX 6 speed but I think it may not be strong enough. 

[RustyCrankshaft]

Modern driveline has options for a TKX in place of a top loader. Considering one to get OD in my 64 Galaxie. Cost of the TKX vs a GV is very similar by the time it's all said and done.