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Discussion Starter #1
I remember seeing somewhere a chart that showed the Powerband of a stock LT1. I seem to remember the HP and Torque was pretty level and started out at low RPM. Does anyone have this chart or know where its at? I have a 94 Caprice 9C1 and will be transplanting it into a car similar to an Anglia (48 Hillman) Engine will be rebuilt fairly stock, most emissions controls removed. Right now the rear end ratio is 3.09. I picked up a 9" Ford today and it has 2.75's too high. Trying to decide whether or not to get 3.00's or 3.25's. Will be more of a cruiser. Car only weighs 2000lbs vs. the Caprice's 4500lbs.

Thoughts/Ideas?
Marty
 

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I would go with 3.42's personally. It'll give you a nice steady pull through first and will also still maintain your cruisability (provided you are running the 700r4 tranny which I believe those came with).

I think they had a powerband of something like Idle-5200 RPM. I know the TPI's had a lower top end due to their lengthy runners however this was corrected with the LT1's shorter runner design.
 

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Discussion Starter #3 (Edited)
Yes, 4L60E Trans, 29x15.5x15 Sportsman Tires.
I like the idea of fuel economy when cruising but would like the torque when "fooling around"
I could get lower, 3.50's or so...now is the time as I will have to go through the diff....anyone got a spare Trac-Lok for a 28 spline 9" they want to part with?:) :
 

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The 9C1 had a 3.08 in it stock. A lot the guys upgrade to 3.73s. With the 255/50-17's, it is supposed to still be very practical for highway drving. It is the hot thing to do.

4.10s if you aren't going to cruise at more than 70 MPH.

3.08s at like 80 MPH and the 4L60E is like 2250 RPMs, I believe. I didn't have a tach in my 9C1 until I upgrade the gauge cluster, then I sold the car.
 

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Well lets see the Impala SS's with the 260 Horse LT-1 that you have would run 14.9 stock with a 3.08 rear. Now considering that car weighed 4000+ pounds you should be running in the high twelves with the same drivetrain in your 2000 pound Hillman. To be honest I would go with the 3.00s.
 

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With tires that tall, with 3.00 gears, 65 mph will be around 1600 rpm. You could go all the way up to a 3.73, and cruise 65 at 2000 rpm. So, somewhere inbetween should fit you fine. Did you have cruise rpm in mind?
 

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I have a 94 Z28 with a stroked LT1 with a 3.42 gear I still get 18 MPG on the highway, turning less than 2000 [email protected] 60 MPH. It will still push you back in the seat from a stand still and get good gas mileage to boot. I haven't turned any 1/4 mile passes, but in the 1/8 she ran in the mid nines with very traction limited 60 foot times.But, I'm not totaly sure if the 4L60E from the Caprice has the same gearing as the 4L60E in the Z28's.
 

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I have a '95 Firehawk and with a ton of work I'm still getting 15-17 mpg. I'd go with 3.oo. I wouldn't go too high because you want a cruiser, not strip car.
 

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3.00 are going to give you way more top end than you need. Unless you plan on cruising at 90+ mph you certainly do not need this high of gearing especially with your overdrive transmission. The higher you go, the more of a dog its going to feel like on your lower powerband. With 3.42's you could get some nice acceleration, and probably not even notice a difference on the top end.

And with the weight of the car you really have an ideal setup where you can obtain some wicked acceleration and still have some great top end/cruisability. Your mpg are not going to suffer.
I am running a TPI setup with 4.10 gears in a 5000lbs truck and still manage 14-15 mpg. That is with no overdrive.
 

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He's got a Ford rear, and you guys keep giving him gears recommendations for GM rears. I didn't put tire size in mind when I said go with 3.00's. I'll change my gear recommendation to 3.50. If you end up with a high gear you can always leave it in third gear on the highway.
 

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My apologies on not paying enough attention. However the same idea applies and I'd still go with a mid 3 gearing.
 
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