OK - before you all flame me and tell me to use the search function, I already have and can't find the info I am looking for. Here is my question:

I have a 1988 IROC Convertible, with the 305 TPI engine and 700R4 trans. I currently have the "highway" gears - 2.73 with POSI and would like to swap them out for 3.23 or 3.42. I cannot find any detailed instructions or steps which outline the process well enough to follow. I would like to know:

1. What parts are required specifically
2. What are the speedometer issues, as I have heard you cannot get the 3.23 speedometer gear wheel anymore
3. Do you have to do anything with the axle
4. Can I use my same carrier
5. Can this all be done without major "invasive" surgery to the transmission or axles

Any help would be appreciated!!

Pete Young
1988 IROC-Z Convertible, Bright Red
305 HO PRI, 700R4 Posi
51K Miles

 

1) gears, install kit, oil, posi additive
2) no idea try this
3) remove them, can't get the carrier out with them in
4) yes
5) there's nothing to do to the trans, other than maybe the speedo, do you know what an axle is?

 

Ede -

Thanks for the repsonse. As for your answers:

1) Can I get used gears, or would new be the best option. If new, do you know of any good sources.
2) I will try searching again, but the real issue is that I DO need a new speedometer gear wheel(s) right? Once I change the gears this will throw off the calibration...?
3) How hard is removing the axles? Do they just pull out, and if so, how much of the wheel/brake stuff has to be removed before they come off?
4) Thanks
5) Yes, but I was wanting to verify that the splines were the same for different gears, and there are no changes necessary

Any other posts welcome.......

 

EEK! Dude you want to see this done at least once before you try it yourself IMO. I mean no disrespect to your abilities and all but there are too many little things that need to be right or you will only be wasting your good money and time. Having someone with experience help you out would be invaluable. Maybe you can hire a cool shop to get the work done who will let you watch.

As far as parts go you should be able to get offset gears to work on that carrier and you will need an install kit. Summit has all you need. Good luck

 

you could get used gears, lot of people do, i wouldn't

yes differant gears will change the reading vs the actual

10 bolt axles just pull out, remove the brake drum first, since you're asking this i'd stop right now and find someone to do the gears

gears have nothing to do with spline count, again since you're asking i'd find someone to do it for you or do a lot more research, which i guess you are here. you're asking some very basic questions to a pretty indepth mod.

 

yah ill agree with the last guy... it is a pain to do these if you dont know what youre doing. i got into doing my rear end without any previous knowledge on the subject. things HAVE to be almost, if not perfect. it took me a month to work out all the bugs from the rear. i must say though i think that the end did justify the means