Also found a different gear set and installed them hahahahah thats part of getting older and and maybe, a bit slacker on things
OK problem soled LOL I found the original sticker from inside the donor glovebox. It tells me it has a GT5 4.1 ratio with G80 locking diff. So the only option would be to go for an overdrive Re the transmission it says MX1- 3-speed auto as well as V02 H.D. transmission OI so is this a heavy duty turbo350 or ???
I would ***ume a turbo 400. I don't know the availability of American parts, but the Allison 1000 6 speed from a Chevy or GMC pick-up will give you the highest overdrive. If you can't find one or they are too pricey, any Chevy overdrive automatic (a 700R4 may be a direct replacement, others would know more than I) will help and you can change your rear end gears to 3.73 or 3.42 and gain more. All the higher gear sets should fit your carrier. As I stated earlier, 16mpg isn't bad and higher gears might not get you much more.
an overdrive unit sounds like the best option that way I can choose when to throw it into overdrive when out on the highway. You suggest a 700R but I haven't heard to many good things about them. I was told they are not very strong or is the 700R4 a heavy duty version?
I'm not too worried about getting extra mpg just would like to drop the revs from 3000 at 63mph to something between 2000 - 2500rpm
My knowledge of GM isn't the best, but I think the 700R4 is built on the turbo 400 design. I have heard that they take more power because of their hydraulic circuitry and they are heavier weight wise. I think maybe there has been more done as far as aftermarket hop-up on the turbo 350 and its overdrive counterpart because of the weight issue Chevy freaks clue us in!
My truck has 4.10 gears as well. If I can get even close to 16 mpg I'd be happy. I plan to run pretty tall tires which should help rpm's a little. I have an old F250 with those gears and it cruises nicely at 65-70.
Keep us informed as to the mileage you get. I'm in the process of building mine and would like to keep it somewhat affordable to drive : )
A 4L80E is the heaviest ****** from Gm other than a allision, after market rebuilders, offer them in a 6 speed, they are 4 speed over drive stock you will find all the info on the Web
I was talking to a friend who is a mechanic and he suggested the 4L80E as my best option and he is going to try and find me one at a good price
The Jalopy Journal
