I am currently in the tear-down step of my tear down and rebuild of my 76 F250 highboy460 4x4.It was primered in white grey and black to look like camo. So I called it the camo-beast.I now have it half primered in black. But anyway. I am debating what would be better to put in it. It has an automatic on the floor right now but it obviously was not stock as when it is in park the shifter hits the dash and alot of times will not go in park. It is also slipping a little and hard to get in the right gear I think the linkage is stretched out a little. It leaks tranny fluid bad and I am tired of it. I dont know what would be better for making a mean truck. I am going to use this truck as show/offroad/occasional pulling/just an all around bad-@$$ truck.I plan on pulling the motor and going through it as it smokes out of one side and needs a tune-up. I will probably bore it and do some goodies to it. So should I go with an automatic or 4 speed and if so what type.

 

Primer paint will not protect the sheet metal from moisture and your truck will rust under the paint. You can find out more paint info in the Bodywork forum.

I would rebuild the C6 you have now.

 

Which tranny you use is your personal preferance. An automatic is nice in busy city traffic where you are stopping and going all the time. I personally like my 4 speed manual granny boxes (NP435 and BW T-18). They have a nice low crawling gear for puting through the trails. They work great for pulling stumps, and other vehicles out of the muck. They really come in handy when you are about to get stuck yourself, it gives you tons of low speed torque for climbing out of tough spots. I think manuals are more fun to drive also, you have a lot more control of the engines power. If you put a 4 speed granny box behind a healthy 460, you'll have one hell of a mud throwing, stump pulling monster! Also if you do decide to go with a manual, DO NOT go cheap on the clutch! You will need a stout clutch if you plan on installing big tires and a lift. Centerforce makes a good clutch for what you are going to build.

 

I currently have a 74 F-250 highboy with a 390 which originally had a C6 automatic. When the engine was rebuilt I decided to convert it to a 4spd manual. It was the best decision I ever made. The 4spd is way more versatile than the automatic. If you are going to use your truck for offroading or pulling its the only way to go. The 4spd allows you to use compound low for crawling and in conjunction with 4-low it vertually creeps over things at an idle. Using this combination I can creep down a steep hill with a full load of wood above the racks and I don't even need to use the brakes. On the other hand the 4spd also allows you to make a positive lock without loss of power unlike the automatic. And frankly the 4-spd is just tougher, stronger, and more reliable in my opinion. If you do decide to install the 4-spd make sure you purchase the one made by "Borg Warner". This was the 4-spd used in the 2WD versions and it turns out that it is much better built and much stronger than the "New Process" offered in the 4WD versions of the same year. Around where I live all of the offroaders choose the "Borg Warner" just for that reason. There is however, a down side to installing the "Borg Warner" 4spd. It requires some modification to connect the linkage properly to the NP205 transfer case and the tranny mount as well. This modification consists of adding square tubing to the tranny mount and the shift linkage of the transfer case in order properly allign everything. You also need to make a custom drive shaft from the tranny to the transfer case. I really see no downside in converting your truck to the 4 spd.

 

The automatic torque converter can put almost twice as much torque to the wheels than a manual can in any gear. The planetary gear system makes the automatic a stronger transmission than a standard which is limited by case strength. The automatic can also be put in low gear for running down hill to keep from overheating your brakes. The auto does not have the granny low that a manual does tho. You can get wide ratio gears for the C6 from Ford or by using parts from an E4OD.

 

Again it really depends on what you prefer, I like the 4 speed better. Especially behind a 300 six, automatics rob a lot of power from an engine. Engines that produce less power work much better behind a manual box.