GMC 3.42 final drive

philip l. stewart

New member
Dec 16, 1997
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Arch, M.J., et. al.---

I installed Cinnabar's 3.42 final drive about 5,000 miles ago and like
the others who have commented to this thread, I've been quite pleased so
far with the results. The 455 in my '76 230 Transmode has noticeable
more power now at cruising speed with little speed fall off on most of
the commonly encountered Interstate hills in Tennessee (Monteagle
Mountain excepted).

I installed it myself with the help of my wife who operated the shop
jack handle as I manuvered it into place, so I know it can be done with
a few tools, jack stands and a shop jack. However, if you can find a
shop that will install it for you at a reasonable price, I'd recommend
that route because it is hard work. I couldn't find such a place in
Chattanooga which would do it at a reasonable price.

If you do order one of the Cinnabar units, I recommend talking to Wes
Caughlin about getting the unit shipped without the cover pan and gasket
installed. They used silicone sealant on mine and because I didn't want
to mess up the seal, I struggled a while trying to get the assembly in
postion with the cover on. There was just not enough room for an easy
fit until I removed the cover and then it slipped right into place.
Fortunately I had a spare gasket which I used to replace the one I had
to scrape off when I removed the cover.

In summary I would recomend the the 3.42 to anyone who's not already
satisfied with the acceleration and hill climbing characteristics of the
stock 3.07.

Phil Stewart
 
Phil,

Is your 455 running OK?? I went over Monteagle on cruise control last
time thru. I still have the 3.07 ratio.

Bill
'73 230