Cinnabar 3.42 vs Caspro 3.55

D

dave lowry

New member
Jul 7, 1998
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I'd like to gain some performance without sacrificing reliability or
spending any more than necessary. I am told that besides keeping the 455
well tuned, I'll need to raise the gear ratio from the stock 3.07, and
that the 2 most common ways to do this are to install either a Caspro 3.55
Power Drive (ahead of the transmission), or a Cinnabar 3.42 final drive
(after the transmission).

The Caspro unit is considerably less expensive than the 3.42 final drive,
and somewhat easier to install, but I've been told that I should not
install it if the transmission has not been recently overhauled because the
tranny won't take the added torque, and would soon fail. I have no record
that my tranny was ever overhauled, though at 93K it shifts well and
doesn't make funny noises or burn fluid.

Can any one provide direct testimony confirming this failure tendancy? If
not, I'll have to presume such comments are either theoretical or, more
likely, designed to steer customers toward greater profit.

TIA

___________
Dave (& Dege), '76 Royale /_][__] [_] | "SR JAMES"
Santa Barbara, CA *0-------OO--* (our hobby)
 
TIA,
I have installed several Caspro finals and have never heard from the owners
again about the unit. I have talked with several other people who have the
full Caspro set up and have had no bad reports. In the Caspro sales talk
Chuck Stoddard put on at the MB Intl. rally, he stated that he has not had
a failure, said it twice in a row so I would tend to believe him.

I too would be interested in any comntrasting experiances because I
recomend the set up to anyone who asks and will listen.

Hope this helps,

Jim Bounds
- -------------------

>I'd like to gain some performance without sacrificing reliability or
>spending any more than necessary. I am told that besides keeping the 455
>well tuned, I'll need to raise the gear ratio from the stock 3.07, and
>that the 2 most common ways to do this are to install either a Caspro 3.55
>Power Drive (ahead of the transmission), or a Cinnabar 3.42 final drive
>(after the transmission).
>
>The Caspro unit is considerably less expensive than the 3.42 final drive,
>and somewhat easier to install, but I've been told that I should not
>install it if the transmission has not been recently overhauled because the
>tranny won't take the added torque, and would soon fail. I have no record
>that my tranny was ever overhauled, though at 93K it shifts well and
>doesn't make funny noises or burn fluid.
>
>Can any one provide direct testimony confirming this failure tendancy? If
>not, I'll have to presume such comments are either theoretical or, more
>likely, designed to steer customers toward greater profit.
>
>TIA
>
>
>
>
> ___________
>Dave (& Dege), '76 Royale /_][__] [_] | "SR JAMES"
> Santa Barbara, CA *0-------OO--* (our hobby)
>
>
>
>
Jim Bounds/Co-op Motor Works Orlando www.gmccoop.com
 
Does it not seem logical, that by reducing the ratio from 3.07/1 - 3.42 or
3.55/1 that this would decrease the torque required to turn the wheels? Or am I
wrong? Darren

> TIA,
> I have installed several Caspro finals and have never heard from the owners
> again about the unit. I have talked with several other people who have the
> full Caspro set up and have had no bad reports. In the Caspro sales talk
> Chuck Stoddard put on at the MB Intl. rally, he stated that he has not had
> a failure, said it twice in a row so I would tend to believe him.
>
> I too would be interested in any comntrasting experiances because I
> recomend the set up to anyone who asks and will listen.
>
> Hope this helps,
>
> Jim Bounds
> -------------------

> >I'd like to gain some performance without sacrificing reliability or
> >spending any more than necessary. I am told that besides keeping the 455
> >well tuned, I'll need to raise the gear ratio from the stock 3.07, and
> >that the 2 most common ways to do this are to install either a Caspro 3.55
> >Power Drive (ahead of the transmission), or a Cinnabar 3.42 final drive
> >(after the transmission).
> >
> >The Caspro unit is considerably less expensive than the 3.42 final drive,
> >and somewhat easier to install, but I've been told that I should not
> >install it if the transmission has not been recently overhauled because the
> >tranny won't take the added torque, and would soon fail. I have no record
> >that my tranny was ever overhauled, though at 93K it shifts well and
> >doesn't make funny noises or burn fluid.
> >
> >Can any one provide direct testimony confirming this failure tendancy? If
> >not, I'll have to presume such comments are either theoretical or, more
> >likely, designed to steer customers toward greater profit.
> >
> >TIA
> >
> >
> >
> >
> > ___________
> >Dave (& Dege), '76 Royale /_][__] [_] | "SR JAMES"
> > Santa Barbara, CA *0-------OO--* (our hobby)
> >
> >
> >
> >
> Jim Bounds/Co-op Motor Works Orlando www.gmccoop.com
 
Dave,
Be aware that there are several final drive ratio's available for the
GMC. I have a 3.55 final installed by Buskirks with a 403. Also
available are a 3.21 which is a toronado gear, 3.42 from Cinnabar and
there is a 3.67 also available from Buskirks. Along with the larger
exhaust system and the new final drive it make mine pretty peppy! The
choice is really yours, because they are are all good choices depending
on how much you really what to spend.

J.R. Wright
GMC GreatLaker
77 Eleganza II
Michigan

>
> I'd like to gain some performance without sacrificing reliability or
> spending any more than necessary. I am told that besides keeping the 455
> well tuned, I'll need to raise the gear ratio from the stock 3.07, and
> that the 2 most common ways to do this are to install either a Caspro 3.55
> Power Drive (ahead of the transmission), or a Cinnabar 3.42 final drive
> (after the transmission).
>
> The Caspro unit is considerably less expensive than the 3.42 final drive,
> and somewhat easier to install, but I've been told that I should not
> install it if the transmission has not been recently overhauled because the
> tranny won't take the added torque, and would soon fail. I have no record
> that my tranny was ever overhauled, though at 93K it shifts well and
> doesn't make funny noises or burn fluid.
>
> Can any one provide direct testimony confirming this failure tendancy? If
> not, I'll have to presume such comments are either theoretical or, more
> likely, designed to steer customers toward greater profit.
>
> TIA
>
> ___________
> Dave (& Dege), '76 Royale /_][__] [_] | "SR JAMES"
> Santa Barbara, CA *0-------OO--* (our hobby)
 
Dave,
One more comment, It is only about three hours labor to install a final
drive and you have to remove & reinstall the transmission which is not
as easy to install the Caspro unit. To be honest if you can't remove
the transmission yourself the cost is almost the same with 10 to 12
hours labors charges for the caspro unit and a little over 3 hours for a
final drive.

J.R. Wright

>
> I'd like to gain some performance without sacrificing reliability or
> spending any more than necessary. I am told that besides keeping the 455
> well tuned, I'll need to raise the gear ratio from the stock 3.07, and
> that the 2 most common ways to do this are to install either a Caspro 3.55
> Power Drive (ahead of the transmission), or a Cinnabar 3.42 final drive
> (after the transmission).
>
> The Caspro unit is considerably less expensive than the 3.42 final drive,
> and somewhat easier to install, but I've been told that I should not
> install it if the transmission has not been recently overhauled because the
> tranny won't take the added torque, and would soon fail. I have no record
> that my tranny was ever overhauled, though at 93K it shifts well and
> doesn't make funny noises or burn fluid.
>
> Can any one provide direct testimony confirming this failure tendancy? If
> not, I'll have to presume such comments are either theoretical or, more
> likely, designed to steer customers toward greater profit.
>
> TIA
>
> ___________
> Dave (& Dege), '76 Royale /_][__] [_] | "SR JAMES"
> Santa Barbara, CA *0-------OO--* (our hobby)
 
3.07 all the way, man. Upgrades like a 3.67 are way out of my budget for
now. Darren

> In a message dated 5/29/99 3:07:54 PM Eastern Daylight Time, powerjon

>
> > The
> > choice is really yours, because they are are all good choices depending
> > on how much you really what to spend.
>
> So the 307 is not good enough for the motorhome? Does anybody have a 307 in
> there motorhome or am I the only one? I do what my girlfirend tells me to
> do:), Its better than rice crispies.
>
> Scott
 
Thanks guys. (Jin, John & Rick) I particularly appreciate being
straightened out on the installation. I had been led to believe that the
Caspro unit was the easier to install. Insted, it sounds like the extra
labor could easily offset any savings in the cost of the parts.

Sounds like the Caspro unit might be the better choice if he tranny was
alread out for another reason, but a new final drive might otherwise make
better sense. As usual, the collective wisdom of GMCnet will allow me to
make an informed choice.

___________
Dave (& Dege), '76 Royale /_][__] [_] | "SR JAMES"
Santa Barbara, CA *0-------OO--* (our hobby)
 
Arch if everything is up to snuff with the tranny, Mondello told me that he
has ran 750HP on it hooked to a dyno.He thinks its one of the strongest
trannys built.

>Rick
>
>I agree with you and have been waiting for you to comment. Now lets take
>theory one more step. Why not 3.67 instead of 3.42? I am looking at some
>of the motorhomes today running 5.32. We are a long way from that. The
>engines they are running are about the same size as ours. The last few
>surveys we have done have shown that there is a lot more trouble with
>trannys than front wheel bearings. As you say Rick if we want to unload
>the work off the tranny then jump on the gears. Seems to me that we
>need to talk about this with no canned answers. Anybody running some
>real crazy gears out there----------------you I want to hear from!!!! Yes, I
>have read the article in GMC Market Place.
>
>Take Care
>Arch 76 GB IL
>
>In a message dated 5/29/99 4:20:03 PM Central Daylight Time,

>
>> Either one would be an improvement to your GMC, but I lean toward the
>> gears.
>> My .02.
>>
>
>
Tom & Marg Warner
Vernon Center NY
1976 palmbeach
"The beautiful Mohawk Vally"
 
I have a 3.07 and it works fine. Can't say it is a greyhound tho!

>3.07 all the way, man. Upgrades like a 3.67 are way out of my budget for
>now. Darren
>

>
>> In a message dated 5/29/99 3:07:54 PM Eastern Daylight Time, powerjon

>>
>> > The
>> > choice is really yours, because they are are all good choices depending
>> > on how much you really what to spend.
>>
>> So the 307 is not good enough for the motorhome? Does anybody have a 307 in
>> there motorhome or am I the only one? I do what my girlfirend tells me to
>> do:), Its better than rice crispies.
>>
>> Scott
>
>
>
Tom & Marg Warner
Vernon Center NY
1976 palmbeach
"The beautiful Mohawk Vally"
 
>In a message dated 5/29/99 3:07:54 PM Eastern Daylight Time, powerjon
>writes:
>
>> The
>> choice is really yours, because they are are all good choices depending
>> on how much you really what to spend.
>
>So the 307 is not good enough for the motorhome? Does anybody have a 307 in
>there motorhome or am I the only one?

Nope. I have the 3.07 in my Palm Beach. Before I chased down all of teh
vacuum leaks and other misc. stuff that impacted the power, I''d have gone
to the 3.5 in a heart beat. Now, unless I decide to two, the 3.07 does fine
for me. It pulled the grades between Albuquerque and Soquel at 50-55 MPH.
So, I find it acceptable. OTOH, when I do need to rebuild the transmission,
I plan to put the 3.55 in.

I do what my girlfirend tells me to
>do:), Its better than rice crispies.

Yes, but does she go snap, crackle, pop, when you pour milk on her????

Henry

Henry Davis Consulting, Inc / new product consulting
PO Box 1270 / product readiness reviews
Soquel, Ca 95073 / IP reviews
ph: (831) 462-5199 / full service marketing
fax: (831) 462-5198
http://www.henry-davis.com/ http://www.henry-davis.com
 
>So the 307 is not good enough for the motorhome? Does anybody have a
307 in
>there motorhome or am I the only one?

I have the 3.07 and can spin the tires.
I don't think I need much more torque...

Dave
73 Sequoia
 
>
>and speed up way too much going downhill. For many parts of the country
it
>would be just fine.

I was just being somewhat of a smart-ass. I know that the lower gear ratio
is an improvement, especially in hilly areas. One of these days I may even
install one. But I do most of my traveling in flat areas and I don't do any
towing. So its not high on the priority list. I also have headers and the
Howell EFI system so that probably gives me a bit of extra torque too.

Dave
73 Sequoia
 
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