Need gear ratio info for a saginaw 4spd

[duckblaster67]

I'm hoping someone here knows the gear ratios for a saginaw 4spd from a 1980 V6 Monza. It's now behind a V8 and I'm trying to figure out a good tire size for it. It's a bit low geared right now.

[crawfw]

1980: No more V8's or 5-spds this year, so only one Monza 4spd was offered and it came with a low gear of 3.50:1. (However, the Chevettes "still" had their 3.75:1 ratio available and continued to until their last year of production in 1986.

This was copied off the hbody.org/hbody FAQ website. A lot of useful info but not all may be 100% accurate. The remaining ratios for 2nd 3rd and reverse can be found on that site. Here's the link

http://h-body.org/library/hbodyfaq/index.html

[cjbiagi]

I am not sure what ratio came with the V6 but 3.50 seems awful low for a a torquey V6.

[crawfw]

Yeah that seems really low for a v6. I just copied from the hbody FAQ. If he could disengage the clutch and put the trans in first gear, it could be figured out as long as he knows the rear gearing. Another way might be just knowing the gear spacing while driving it. I've had both the 2.85 and 3.50 sags. One distinctive thing about them is the rpm drop between certain gears. My 2.85 seemed wide going from 2nd to 3rd. My 3.50 trans seems wide between 3rd and 4th. Other than pulling the trans I'm not sure how to tell. Pulling the side cover seem too messy and hard to reassemble in the car.

[Monza Harry]

Duck Blaster do you remember how many grooves were on the input shaft (or have a pic you could look at) before you installed it? Somebody here a year or two back had posted here the corresponding Ratio's to the groove count (not to be confused with the spline count) on the input shaft. I may be able to find out from my brother (as he used to blow them up like crazy and therefore was out chasing them years ago) if you aren't able to find the thread, I am sure one of the 3 pedal lovers here will be able to help as well (they are many and loyal as all hell to the extra pedal )Harry

[marco_1978_spyder]

Found this on the web..

SAGINAW 4-SPEEDS (CAST IRON)

0 LINE INPUT -2.84/2.01/1.35/1.00

1 LINE INPUT - 2.54/1.80/1.44/1.00

2 LINE INPUT - 3.11/2.20/1.47/1.00

3 LINE INPUT - 3.50/2.47/1.65/1.00

V8's mainly used the 2.84 1st. with a 3.08 rear. Cosworth Vega, 3.11 with 3.42 and 4.10? rear gears. and possibly 77 V8's used the 3.11 gear with a 2.73 rear.

L4's and V6's from' 78 up used the 3.50 1st gear. The ratios in this version, are the exact same as the stock 5 speed. The additional gear was the OD gear.

Vette's and Camaro's used the 2.54 version. Thats the one I'd like to find.

[duckblaster67]

I'm sure the 3.50:1 ratio is correct, because it goes thru the gears fast in a short distance! I'm gonna try to find a taller wheel & tire combo to get some of the top end back! Thanks everyone for your help!

[hammerdown7]

I'm sure the 3.50:1 ratio is correct, because it goes thru the gears fast in a short distance! I'm gonna try to find a taller wheel & tire combo to get some of the top end back! Thanks everyone for your help!

What is your R&P?

By the way, Cosworths had 3.73 with the 4-speed and 4.10 with the 5-speed.

Dick