Dilema.... Help Please

[tkeduk8r]

Well about 3 years ago I decided in the name of gas milage to swap out my 3 on the tree and striaght six to a 305 and a 2004r auto trans to go with my stock 3.73's and 31 inch long trail t/a's.... this combo has worked well, getting me 19-20 mpg on a good tankfull in the summer, but ive noticed a little slipping in the trans and the cheaper rebuild I decided to go with I believe is letting me down... so after discussing with my wife Ive decided to go back to a manual again, rather than spend 900-1200 on a good rebuild of my 2004r. When I first started this project, I wanted to keep the manual, BUT it wasnt until swapping in the 2004r that I discovered the A833 4-speed OD. SOOOO a couple weeks ago I head out to a local jyard and low and behold find a truck with the A833 and its mostly complete... WOOHOO!!! HE is crushing but I ask him to keep it for me (he is a parent of one of my students) and offers to bring it over to my school and I can have what ever I want off the truck for 60 bucks.. even better right, well I go out there last week and ask him if he has time to bring out the truck to the school and to make a long story a little less wordy... He mistakenly CRUSHED it thinking I wanted a different truck.... ARGHHHHH... forward two days... So he shows up at the school with a 83 SWB (REALLY RUSTED) with a SM465 and 250 out of the yard... didnt ask... it just shows up... SO I figured since the price was right I'd swap everything back over to manual on my 74 and go with teh sm465 until another A833 pops up... I had a couple of students stay late tonight to help dissasemble the 83 to find out that the "GQ1 Standard Axle" in 83 meant a 2.73 ratio instead of my 74's 3.73.... SO MY QUESTION IS... should I swap the speedo gears to the correct ones for the SM465 and keep my 3.73's (remember milage is a factor here) OR swap the 2.73 axle fromt eh 83 into the 74.... Im going home to sleep on it and hopefully you all with have some good opinions for me!!!! The truck is a combined highway intown runner... I travel 20 miles one way to work on 55 mph roads with a twice a month hour an a half blast down the freeway at 70.... lets hear 'em!!!!
--Mike

[tkeduk8r]

ttt

[jermasaurus]

That is nice mileage you got with your combo. I would personally get another 200r4 or 700r4 to replace yours. Did you add a trans cooler besides the one in the radiator when you put the 200 in? The heat is what kills the 200/700r4.

I put a 305 back in my truck, performer intake, holley 600cfm carb vacuum secondaries.
700r4
2.73 rear end 275/60/15 tires

I get 15 mpg on a GOOD day

I would love to get that 19-20 you get.

I would personally get another 200 or 700 trans I think it is a .7 to 1 Ratio in OD I could very well be off on that though

[DubDubU]

Here's a calculator to help with the math.
http://www.angelfire.com/fl/procrastination/rear.html

[N2TRUX]

I have to agree with jermasaurus that you should have kept the auto. If you drive with a heavy foot at all the 2.73 will get crap for mileage because they don't generate any torque. I have had seeveral trucks with 3.42's and 3.73's. If you want mileage go with 3.42's as the 3.73's will always net you at least 1.5 mpg less.

[tkeduk8r]

thanks guys.. thats kind of what I was thinking too... I love teh 3.42's in a truck with that sm465... ut I didnt know bout the 3.73's.....according to the calculators id be at about 2800 rpm at 70 with the 3.73's and 2000 (where im at now w/the 2004r) at 70 with teh 2.73's AND i agree that it'd be a dog's dog around town (and poor milage aroudn town too)... oh well... I also started diggin this morning and I forgot the length of the 465 is shorter that the th350 or 2004r which means drive shaft issues since the donor is a short bed... so Im really questioning it at this point....

this all became appealing because I could do this for next to nothing (under 100 bucks), BUT it may mean too many mods at this point.... I dont mind performing the mods, but if the swap ends up costing close to the cost of the bulletproof 2004r ($900-1000) that would defeat the purpose, other than I do like shifting a manual trans better...

Thanks again for the responses.. and ill see if I can post some pix of the shorty is anyone needs parts off of it....

--Mike