Back end questions

Post Reply
Newbie Poster
Posts: 1
Joined: Sun Jul 23, 2006 11:58 am
Location: Salt Lake City, Utah

Back end questions

Post by Fullmonte » Sun Jul 23, 2006 12:24 pm

Hello Jim,

I just cruised through your website ( and recognized your name from the posts you have made on the FGMCC site and felt like I'd found someone I can trust to give me some good information about my old 71 MC.

A few years ago I inherited the Monte my "old maid/school teacher" auntie. She bought it off the lot new; it had 54K miles ont it when I got it(I swear this is true). It is a stock 350 w/o air and no bells on whistles to speak of. It has the 350 th transmission, with an open differential, I think. (When it is up on the lift and in neutral, you turn one wheel one direction and the other wheel turns the opposite direction.)

I never had my own car growing up and always envied the "car guys" at school or my neighborhood. So, since getting the Monte, I have tried to do a few simple things to increase the performance like install headers, a HEI, Eldelbrock Performer manifold and 600 cfm carb, and the usual dress up stuff. Plus I have a mild cam and plan to install either Vortec or aluminum heads in the future.

My next project is to change the gears in the rear end, and this is
where I am totally in the dark. I hear so much about posi's, limited
slips, lockers, Eatons, Detroits, etc., that I am in no real position to decide what to do, and I don't want to get taken by some "fly by night" outfit who are not experts. That's where you come in. You know differentials, and you know Montes.

Here's what I want: Better performance from a stop. I don't want to smoke the tires to the rims, but getting a good squeak is always a rush, and it make the grandkids giggle. I hardly ever take this car on the highway. It is mostly for around the town cruising and taking the family for rides. I do not now what gears are in it, although it sure seems to cruise effortlessly at 65-70. I do know is that it is a 10 bolt, as I have
counted the bolts! Beyond that, this is all Greek to me.

I kind of like the idea of posi-traction where I can get both wheels working for me, but have no idea if it is possible or reasonably affordable to get better gears, posi, etc. all in the same package, and what is the best set up given a mildly upgraded 350 and my current transmission?

Thanks for your help, Jim. Good luck with the website. It is well done!

George Knight
George Knight


reply to your questions

Post by monzaz » Tue Jul 25, 2006 1:16 am

On your questions, well more info on the exact things done to your car
would be better like the exact cam or some specs from it. Being stock
motor I would assume it is a dish 350 with smog type 76-80cc heads low
compression motor. You did not specifiy which eldebrock manifold you
bought...I again would assume it is the performer step up from stock... ???

Size of tires total diameter helps too. I need to know how much off the line you want... lol. The usual upgrade to an all around perky performing car would be the 3.55 gear set. Still some freeway driving but a definete better launch then a 2.73 which is most likely what your rear has...I have parted out plenty. Posi is not a problem either. Nice Auburn street posi will make the car pull and grip even better on lauches.

Sounds like the car should run well as is have you tried to tinker with that ignition curve and total advance in the car? Most people just set the intial timing (just of the idle timing) and leave it... You need to find out what the cars is doing when all the advance is in at 3000 RPMs you want it at about 36 - 38 degrees in quick. Most people are just plan clueless about how much ignition will totally wake up a car through out the whole power range. Talk later after you get some more info. Hopefully we can move this to the site. Take care, Jim

Hope you will get me more info , Jim

Post Reply