3.23 or 3.55?

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Golden Scamp

Golden Scamp

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I have the idea that I am going to build a 400 HP 318 in my '71 Scamp and was trying to decide what gears would be best for my needs. I currently run on a 2.76 gear/741 case in an 8 3/4 rear. It has a 904. Everything is original but not for long. I have seen several sure grip units but do not know which gear will be better suited for what I want to do with it, which is strictly cruising and the occasional 1/4 pass. Can anyone tell me how their set-up's have worked for them?
 
Or any other gear recommendation for that matter? 2.94, 3.91? Thanks for the help.
 
strictly cruising i would go 2.94-3.23 unless you have a OD trans.

then it also depends on what your 400hp combo likes too. the motor may not like those gears.
 
You more than likely can find out for yourself.

http://www.ringpinion.com/Calculators/Calc_RPM.aspx

Just find out all the info about your tires your current gear and input different gears to see what kind of RPM you will running at different speeds.


The reason you need to find the gear for yourself is because you will get different options. It might be just 200 rpm difference.
 
abodyjoe said:
strictly cruising i would go 2.94-3.23 unless you have a OD trans.

then it also depends on what your 400hp combo likes too. the motor may not like those gears.
Click to expand...

I agree joe, a true 400 horse 318 may be a little high strung? Then there's converter choice...oh my:D.
 
i most definitely am very happy with my 355's...yea, kinda revvin at 70, but i dont care. 318's are ment to scream.
 
A 400 hp 318 probably ain't gonna be a torque monster. In fact it'll probably be just the opposite. I'd run at least a 3.55 gear otherwise it might be a slug on take off. If you do build this 400 hp 318 make sure and get a good converter to go with it or again it'll be a slug on take off.
 
My clients seem to find 3.55 will keep the engine snappy and them happy, with most moderate cams, in most conditions, with or without O/D.. my .02..
 
3.23 is a great all-around gear, and my choice, but my guess is a 400hp 318 will prefer 3.91's.
 
Short cruising , this mean highway ? Cause 2.76 in the city will be a dog , 3.55 is a good all around choice for city /highway/strip , on the highway I'm buzzing 3300 rpm at 70 with 3.55 , 235/60-14 tire , not that bad , 3.23 will bring me 76 mph at 3300 rpm. Not a big deal . 3.55 is the best compromise gear imo .
All I need now is traction !! All my car does is spin through 1st and a bit of 2nd gear , your 400 hp 318 should do the same . .
 
Guess it depends on how much RPM you want to spin at when your doing your normal cruising around...I liked the 3.55 in my RoadRunner but for mostly crusing dont like anything over that..right now I think my Dart Sport has the 3.21 rear gears nice for cruising..IF I was gonna go for a few runs at the strip id go 3.55
 
Yes. Mostly highway to local shows and occasionally around town. And who can resist lighting 'em up at a stop light every now and then. Great advice from everyone. Sounds like 3.55 is the winner.
 
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