Gear options and how the do

[PGSigns]

I have a 3.73 in the 66 with a crate vortec head motor with a small cam and a 700R4. Its just a cruiser and would like to pull some gear out. I have a 3.42 and a 3.08. The 3.42 would pull 10% off the cruise rpm and the 3.08 20%. Would like some feed back from you guys running theses two gears and what you think of your setup and how it does. I am thinking 3.42 but the 3.08 would make it really highway trip friendly.
Jimmy

[Palf70Step]

the 3.42 is the best choice in my opinion. I have a 3:08 in my 94 with the overdrive and anytime I get some hill action it wants to kick out of OD. My other truck is a 3:42 and it just cruises. In fact I think the MPG is just a hair better normally.

[PGSigns]

Any idea on the weight difference on your two trucks? I would think the 94 may be 500 pounds heavier.
Jimmy

[Hollow65]

I wouldn't go any less than a 3.42. Just my opinion.

[TJ's Chevy]

3.42 is as tall as you need to go with an OD trans. Unless you add another 100 cubic inches to that motor.

[Keith Seymore]

I think 3.73 is the right choice.

I always default to 3.42 for non-overdrive applications and 3.73 with overdrive.

K

[Clyde65]

I agree with Keith, I have the 3.73's in my truck with the electronic version of the 700 ( 4L60e) it really helps with my small v8 and also allows for quick acceleration when needed as well as highway cruising at 75 with good mileage.

[DLW]

I have 3.42's with my current build. In the past I have used 3.23's, 3.42's, 3.73's and 4.10's.

The 3.23's came stock in my 2000 Automatic Camaro. 3.42's came stock in my other 6 speed manual Camaro. They both did very well behind the LS1. 3.73's also did ok both at the track and on the freeway, but as a cruiser I like the 3.42's.

[blown240]

Not sure if this helps, but, I ran a 2.43 (yup 2.43) in my 51 chevy car with a non OD trans. I would cruise at 80+ and while it didn't have a lot off the line, it was plenty with a slightly build 350.

[verdell]

I have 3.08's behind a really stout 383/700R4 set up. It cruises great and though it'll still burn the tires, I'd go with the 3.42's. I plan on switching from the 3.08's to 3.42's this spring. 3.42's seem to be the best of both worlds IMO.

[chevyrestoguy]

PGSigns-
I'm really interested in hearing about your combo, as I am building something very similar to yours. I also have a 350 with vortec heads, and I'm running a decent hydraulic roller (222/230 @ .050, .509/.528 lift on a 112 lobe center), a 2200 stall converter, along with 3.73 gears (31" tall rear tire).

What is your cruise rpm at freeway speeds? Are you getting decent mileage? I really gave a lot of thought between the 3.42 and the 3.73 gears, and wound up going with the 3.73 because I already had it available. I plan to upgrade to a posi later, and if I choose to go with a higher gear ratio, I'll swap out the 3.73.

[PGSigns]

I'll look at the cam card tonight and see what is was. Mine is the 95 to 2000 vortec crate engine with the hydraulic roller, aluminum duel plane intake. Edelbrock thunder avs 650 and a MSD ecurve. My tire is not near ad big as yours. I think mine are 28.2" tall. Driving it back and forth to work I get about 14 mpg. 20 miles from house to work and 24 stop lights. Sucks some days. Runs 2000 rpm at 65 mph. Trans is a 700 with a Ron Francis lock up controller set about 46 to 48 mph.
Jimmy
Jimmy

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