nice rearend....

[Hittman]

I just wanted to throw out some things to all of you to get some opinions on what I might be able to do with my situation. Bear with me, this gets long....

Last spring I bought an all original low mileage (but low option) '70 3/4 2wd 350 4-speed for a decent price and have been driving it daily since (exept in the rain when I can help it). This is my first of the round fendered beauties and I love it - always wanted one. It had lived it's life on a farm for the first 30 some odd years and sat in a shed the rest of the time. Only a few pin holes of rust in the rockers and the bed floor - very hard to come by in these parts of the country. If it were not for the farmer backing into everything bashing up the tailgate and right rear quarter it would be nearly perfect.

I installed power steering (it's a whole different truck to drive now!) and the usual late model factory chrome 8-bolts in attempt to tone down the "I'm a farm truck" look to it. I tried running smaller tires on it but the low gears didn't allow for me to run much over 55-60 mph with out thinking the engine would blow. I have since put on larger diameter 75 series tires which helped the rpm issue (with out a tach I am guessing still 3500 rpm +) but now it resembles the previously said farm truck I am trying to shy away from.

This brings me to my first issue: I believe I have identified the rearend as a corporate (completely smooth round pumpkin) and I can only assume it has either 4:10's or perhaps 4:56 gears. I assume these were the only options for that rear end and maybe even all 3/4 tons. Is there way to swap the gears for say 3:73's or even 3:08's? Another option (though I know there are some die hards out there who might think I would be an idiot to do this) is to swap the 8-bolt hardware for some 1/2 ton 5 or 6 bolt but understand that to be quite a job anyway. Actually is this even possible and still maintain the same springs and other components? With 8-bolts I am also limited to wheel choices - I would also much prefer the stock ralley's which again directs me to going with 1/2T hardware. Anyone know of an 8-bolt ralley aftermarket wheel - 15"?

My main goal is to have a truck I can drive down the highway/interstate at a comfortable and more fuel efficient rpm. It would make the truck much more useful and pleasurable to drive. Any ideas will be of great help.

Secondly while I have your attention (sorry this is getting rather long) I am a big fan these in short box form and know I probably won't be able to ever afford one.... With that I have considered cutting mine down. However I know that 3/4T 2wd short boxes are...well.....non-existant. Any one out there done this to a 3/4 ton? I know a guy in town who cut his 1/2T down and put a purchased short box on it. I have also seen some info on cutting these frames and just need to get in touch with him for the procedure.

However I would like to use my box and section it. In my case my dent is actually that last 18 inches or so on the passenger side which just makes my box a good candidate for this. The majority of rust on the floor is at the back as well. If I could cut out the back 8" of that I think the dent repair would be much easier and I would be able to salvage an otherwise nice box side. I have seen some pics from you guys who have done this and recently I watched those guys on Trucks! the other day cut down a '66 who of course made it look soooo easy. They actually cut right against the front and back corners as to eliminate a splice out in the middle of the panel and notched around the pockets. Anyone ever done it this way? This would help eliminate any warpage I would imagine and I would think woud be an easier place to grind out the welds instead of smoothing out a seam in the middle of the panel. I realize I would also have to notch around my side marker lights also. Measure 10 times, cut once as the saying goes. Again, has any one done it this way?

For those of you who stuck through this drawn out blog to the end - thank you for your patience! Again any help will be much appreciated.

[Dingfodgy]

Regarding the whole RPM/Rear End Gearing conundrum you're in. Here's what I would do (bear in mind this is my personal preference). First determine the actual R&P set you have- either by poppin' off the rear cover and "countin' teeth" (sounds like somethin' you'd do at a hillbilly brothel!) or jack up the a$$-end and mark the RR tire @ 12 o'clock with a grease pencil or the like and place a horizontal line on the drive shaft. Turn the wheel 1 revolution and count how may revolutions the driveshaft makes (it'll get you close). If indeed you do have the 4.11's or 4.56's- I would swap them out with 3.73's and throw in a good TH700-R4 / 4L60 overdrive tranny. If that's too much then go down to a 3.48 or 3.08 R&P set. I wouldn't mess with swappin' out the drivetrain for 1/2 ton units. If it's a 1/2 ton you really want- sell the C20 and go out and get one....it's much easier than converting. Lastly, in order to shorten a long bed into a shorty requires that front cut be made about 1/2 behind the first frame mounting hole (so I'm told). There's a couple reasons for this.
A. Once done all the remaining mounting holes line up as original (so I'm told).

B. The side profile of the bed is such that we have to take a section out of the middle of the bed in order to get the "lines" right and not look goofy where the bed runs into the cab. The reason they could clip the very front and rear of the '66 on "Trucks!" is because that body style has a straight crease down the side of the bed, whereas our trucks have that sexy tapered body line.

Please be mindful that some of what I said above is pure regurgitation of stuff I've read on here, or at least my interpretation of what was said. Consult a trained professional before embarking on any frame hackage.

L8R.

[Hittman]

You bring up some very good points there Dingfodgy. I guess I did wonder about the body lines not lining up correctly but I thought the hardest ones to align would be at the rear more so than the front due to that taper at the rear. Regardless I see your point and will have to take this into consideration. It is a daunting task and I am not sure I can "hack" it with my limited expertise. But I think I am up for the challenge - I will probably never be completely happy with it until it is a shorty. The frame splice will definately be performed by only a pro - which I am not. There are quite a few threads on this site to guide me through it.

As far as the rearend goes I think I am best to swap the gear set if it indeed can be done. Like so many I too am on a very limited budget and I gather that a manual to auto swap is somewhat cumbersome too (crossmemember/linkage/steering column/etc.) I would guess that I can't just swap out a gear set from any 10 or 12 bolt. I will probably have to locate these new as I am sure this rear is specific to shaft diameter and who knows what all. What do you think?

I do hope to make a winter project out of this - tearing it apart will secure me from having to drive it this winter!

Thanks again for your input.