I current have a TH350 and want to switch to a Muncie M22 4sp....the thin i was wonderin is the 350 has a 1:1 3rd gear and the M22 has a 1:1 4th gear. So by switching to the muncie and gainin a 4th gear am i realy "gaining" anything at all??? the reason i am doing this is for gas mileage..

would the 700R4 be a better swap??
-Roger

Your rpm's will not drop in drive, due to the same final gear ratio.

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68 468 700R4

So basically it's a worthless swap..!
because i want an rpm drop

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Roger Leete, roger@69camaro.com,
'69 SS 355/350 horses

Any gas mileage improvement would be very slight, since they have the same final gear ratio, you would hardly notice if any at all. The major reason to go 4 speed is the fun factor.
So I guess you are right, it would be a worthless swap to you, but to me it makes the car more desirable and worth more.
Ron

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95 Z28 Convertible 6 speed, 70 Chevelle SS 396, 66 Nova SS 327 M21

[This message has been edited by ToocoolZ28 (edited 01-17-2000).]

you would gain some power too from the four speed, cause the auto takes some power about 25 to 30 hp. you would get a little better gas mileage because the engine would not have to pump oil thru the auto tranny, where the four is just bathing in the lube.

Roger,
If you are looking for better fuel economy or a lower RPM cruise range the best option for you would be to go with one of the over drive transmissions such as the 700R4/200R4 or OD manual transmissions. To really take advantage of switching to a four speed with what you have now you would also have to swith to a lower (numerically) gear set in the rear end. The extra gear in the four speed will help you get the car moving with the lower gear set and then when in fourth gear you will be getting lower RPM's and better fuel economy. I say you should look for an OD transmission though. This is the way to go.

Thanks for your help, I think i'm goin to invest in the 700R4. I found one down at the local performance shop for a good price.

Some more questions though: i currently have a 9" rear with 3.89's. about how many rpm's will the .70 overdrive knock off? currently i make 2500rpm's at 50mph on the highway..

another thing i'm about to put roller rocker 1.6 arms on it to give it maximum lift with my cam, i think its around 525. will putting the new rocker arms steal gas mileage? because i know it adds 20hp and valve opening, so the engine is doing more work....
-Roger

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Roger Leete, roger@69camaro.com,
'69 SS 355/350 horses

If my math is correct,I would say with .70 overdrive 2500RPM would now be 1750RPM ,or just take whatever RPM you want and multiply it by .7 for your answer.If amyone is interested. "Randy's ring and pinion" has a RPM calculator on thier site.You can factor in your tire size,rear end gear,trans.,and speed.Pretty cool,and it's free! http://www.camaros.net/forum/biggrin.gifSee it at www.ring-pinion.com (http://www.ring-pinion.com)

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67 RS RAGTOP # matching, 4X4 CHEVY TRUCK

The last post was dead on as for rpm. Isky sells a device called a dream wheel, it will tell you displacement on one side and displacement on the other. The gear ratio part is really cool, it has four variables, engine rpm, gear ratio, tire diameter, and mph. If you have any three you can calculate the 4th. It is good to determine tire dia., or gearing for cruise or racing.

As for the 1.6 rockers, if you have stock Chevy heads you will need to elongate the pushrod holes, and need screw in studs. If you have aftermarket heads go for it.

Steve R.