I want to replace my C6 with a manual trans in my 68' F250. I have a 428 FE and a local salvage yard quoted me $550 for everything i need to transplant, pedal, linkage, trans, etc. the one thing that concerns me is the crank balance. The donor vehicle im getting the 4 speed from has a 390. So i will need a manual flywheel for a 428. My 428 is balanced to 1/2 gram, will i need to take my flexplate, and new flywheel to the balance shop to have them matched?

Also, are the 4 speeds in these trucks any good? Can they handle big tires and 500ftlbs tq? Are there different 4 speeds available? What tranny do i want for my truck and how do i know what im getting from a junk yard? Overdrive would be nice, but i dont think any came with OD stock? I dont nessesarily need a granny gear either. I have heard about the clark 5 speed, but where the hell can i find one of those?

 

I'm not sure about the 428 plate/balance etc, rusty70f100 probably will.

Yeah, the T18 and the NP435 are very strong 4-speed tranny's. I'd say they can handle 500tq on a regular basis. On a T18 there isn't much to wear out/break, it's simple stuff.

If you want a car 4-speed (toploader, non granny gear) talk to Freightrain, he's the man with those swaps. I was going to do that until I decided to do my 5-speed swap.

 

I'd have to echo Ceet's opinion on the NP435. It's basically a 3-speed with Granny. As for top end you have 4th which is otherwise known as the 35-1,000,000 mph gear. It's damn near bulletproof and takes more than I've been able to dish out in multiple rigs to kill it.

 

fling, the NP 435 has a rating of 427 lbs/tq. if your an agressive driver you'll eat the 308L bearing behind 1st gear as well as the taper input bearing. Stock is 7 ball installing, a 11 ball is stronger. A 410 with Sidewinder, 427 heads, headers and cj cam will eat a box by 10,000 miles. Rebuilts were twice a year. Install a thick gauge pressure plate basket, cheap ones will crack and rip apart, not safe or pretty.

Carl....=o&o>....

 

Fling, I would look around a little more for the parts, you can buy a whole donor truck for that kind of money. Have you upgraded to power steering & disc brakes yet?

John

 

I would run it anyway, despite Beemers thoughts. Who uses first gear a 6:1 anyway under normal driving? I surely never did. Those trannys are strong, don't worry about it.

 

Ceet, I have to confess I have a light left foot and a heavy right foot. At 843,000 hard miles any weak points came up. If I was installing a stick from an auto I would use a Top Loader 4-speed, the 435/T-18 are just a wide ratio 3 speed.

Carl....=o&o>....

 

The 428 flywheel is special balanced, so you need to make sure what you buy for it. IF you buy a steel aftermarket wheel, you'll need to get it balanced FOR a 428. Most all are neutral balanced new(for everything BUT a 428). A competent machine shop will be able to help you(they will need a 428 crank to balance the wheel properly). If you buy a factory cast wheel, make sure it shows the piece of pie cast in the back side. It's the factory way of adding the needed weight to balance.

In both of my 428's I had them neutral balanced when they were built. This way ANY wheel could be bolted up and no additional work is needed. Granted it cost a bit for the Mallory metal, but makes for parts changing ease later.

As for tranny?? I run toploaders(car 4 spd) in all my stuff. Holds up well for street hot rodding. Now, depending on what you plan on doing with the truck is how well any tranny will hold up. If you have large tires(like mud type 31"+) any tranny will be hard to keep up with hard launches...especially if it wheel hops AT ALL!!!! This will destroy any stick shift in short order. Any repetative shock load will destroy gears!

Before you cast out big bucks to the junk yard....check the classifieds HERE! I did and you'd be surprised how cheap you can do it. I only had a few bucks getting the linkage parts(pedal, arms, pivot). The heavy items(bellhousing) might cost a few bucks, but they are dime/dozen and not worth a bunch. I had a fellow send the stuff, told me to take what I need and pay a few bucks for it. Not bad for not knowing me from Adam.

 

I need somthing thats gunna last me, I got 33" tires and motor is 422" Cobra valves, ported, Performer RPM, and a Crower 272 cam. So im pumping a little more than a CJ. I am a very agressive driver, and in the off road this thing is going to take serious abuse. If the trans is going to break after a year i dont want it. Can i beef up a stock trans to last or am i going to have to go after market? I dont mide spending some bucks if the **** is good.

 

fling, clearance the 435 synchros .010" below minimum spec, install 11 ball 308L bearing vs 7 ball. Tight or new shifter top with stick, newer sticks had O-rings that gave rubbery synchro action (epoxy solid).This is a bad design to have a taper bearing (input shaft) that wants to walk out of it's race backing into a ball bearing which is designed for radial not thrust loads. Do not set the input bearing on the loose side or too tight or the box will bind and drag causing crunchy shifts. If you don't get aggressive with the clutch and as stated wheel hop you "may get by" as you are running taller tires which adds more driveline and box stress.

Carl....=o&o>....