Wanna do something drastic with my 65 SB

[mikey]

Hi all - been a long time since I have had time to visit here. Glad you guys are still around.

I have a nice little red 65 short bed F-100. I have had it about 10 years now. I want to drastically change the way it rides. Let me explain.

When I got it, I put in a mildly built 390 with a nice cam and sweet exhaust. It was hooked to the 3 speed on the tree with the original 9" open rear. I ran it around like that for a couple years. When I go a few bucks, I swapped out the 3 spd for a 4 spd toploader. Didnt realize that it was a close ratio one - so I was unhappy with that, but decided I would live with it since i had incurred the expense of the tranny, shifter, drive shaft, etc. One day at a car show in the mountains, I got stuck on a hill and the open rear was basically to blame. It was embarassing so i put in a Ford posi - 370 rear. Big mistake. I think the orig rear was something like a 323 or so. Anyway, now the 390 eats the fuel, the truck vibrates a lot more due to the high rpms it turns to go 55, etc. I love my truck, but overall, i am just disappointed with the way it is built. My bad.

So, basically i want to transplant the body and bed onto something more modern and then lower it. Has anyone done this?

Oddly enough, I have a donor 96 mustang GT with a 4.6 / 5 speed that runs great. Anyone ever transplanted the motor, tranny, rear, etc. from one of those into a slick? That would be cool - then I could do a rack and pinion front end with disc brakes - that all seems like it would make the truck into something more like i would want to ride to slickstock with.

Any ideas? Can you guys point me to where folks have done such?

Thanks

Mikey

[charliemccraney]

At 55mph with a 3.70, your engine should not be turning any more than about 3000rpm, probably closer to 2500rpm, either of which is fine. It will run all day like that when in good operating order. If you have a vibration at that speed, something is not in good order.

Some of the weights I've seen posted for these trucks are pretty close to a 96 mustang so the engine/drivetrain package might actually work out pretty well.

Make a list of all of the things you will have to do to make it happen then multiply that list by 3 to account for the things you have not considered and even that may not be enough. It will be a lot of work. Once the requirements have been determined, and you're satisfied with them and you have the skills and space to pull it off yourself, do it.
If you have to pay to have it done, you'll be better off to get the transmission you want or, if possible, have yours converted, and maybe even go ahead and get an overdrive transmission, find the source of the vibration and fix it, and perform your lowering mods to the stock suspension.

[mikey]

Thanks Charlie - good feedback. Does anyone have a OD tranny recommendation to fit the 65 that bolts up to a 390? And you're right, at 55 it turns about 2600 RPM - which would be ok if i can isolate the vibration issue. Is it possible the flywheel is out of balance? Could the toploader be causing the vibration? Clutch Assembly? The drive shaft was made new - presumably it was balanced - i can double check on that. I just don't know how to approach diagnosing the vibration at this point.

All the costs you point out are, to me, pretty heavy in terms of time and effort as well as the money. Maybe the next step is to replace the tranny with something better. Also looking at the DJM dream beams. Anyone had experience with them? How'd you lower the back end to match?

Lots of questions - sorry but thanks...

[Gritsngumbo]

How'd you lower the back end to match?

DJM Lowering brackets and shackles.

[bunchoftrucks]

If there is more than one drive shaft shop in your area I would take the new shaft there and ask them to check the ballance and see if it's right. Check your tranny mount as they have been know to go away and cause vibration as well. I've done many things with these trucks over the last 20 years that didn't work out and/or failed so I just chalk it up as another lesson learned Your 4.6/5 speed sounds pretty good.

[mikey]

This idea hit me for some reason. The 96 mustang in question is a car I bought for my son when he was in high school. Now he is married with kids and the car just sits around. Mice got into it and made a mess of things. One thing I am sure of, it must be one tough drive train because he drove it like he stole it and it still runs like a scalded ape!

Way back in the late 90's the plastic intake on it cracked and that was replaced with the upgraded heavy'd up version. Since then, nothing mechanical has been needed - it has about 90K miles on it. We/he always ran synthetic oil and it was regularly and properly maintained. We put new wires and plugs in this summer.

I have not seen any slicks with a 4.6 yet at least, but for some reason it seems like it might make a good match.

Here is my thinking at this point:
1. Pull the 390 and TopLoader
2. Lower the truck with DJM Dream Beams and the DJM rear lowering brackets and shackles.
3. Leave the 370 Posi rear in place
4. insert the 4.6 / 5 speed - probably no simple task - from what i have seen it looks like you have to also keep all the wiring and electronics, dash instruments, etc and the placement of the ECM might be tricky - not sure how all that might be done. I am thinking my existing radiator (new moden 666) is up to the task. I am sure motor mounts will be an issue along with engine placement to get the tranny in the right place - tranny mounts, etc...
5. consider if I can get disc brakes on the front - I am now running the original drums but added a booster to it a few years back.

My nature is to put together some type of project plan / feasibility study before undertaking this, so any and all feedback from all you experts out there is welcome and appreciated.

[*ryno*]

buy a mm2 front end kit, a lot of the companies offer teh 4.6 motor mount kits, same as a 5.4 i believe.as you mentioned you have the complete mustang, so it shouldn't be too hard. you'll need all teh computer and bs to make it work, or you can order an aftermarket stand alone comp system for the engine and trans.

[fire truck]

I wouldn't waste money on the DJM junk. For the rear you can flip your hangers and put drop shackles on for less than $100.

If you want to swap in the 4.6 use a 03 and up crown vic cross member, then the motor mounts are already there. you may be able to use the rear from the stang too....