If you got a Buick V6 professionally race balanced and installed a different
cam, I'll bet you could get 6,000 rpm out of it. ;^)

Remember that while an overdrive increases road speed at a given engine rpm,
it decreases torque at the rear wheels. The factory overdrive (fifth gear)
in my 2.5 liter Wrangler is pretty much useless for that reason. So if you
install an overdrive or regear, you will probably need to increase engine
displacement to compensate.

Earle

<eselk@surfbest.net> wrote in message
news:1147189246.988163.161920@v46g2000cwv.googlegr oups.com...
> Comments in-line with original text below...
>
> Howard Eisenhauer wrote:
> > What specificly didn't you like about the Buick V6? This is the
> > de-facto standard engine swap of choice so I'm curious what it was
> > that gave you grief- Doesn't matter what tranny you put in there, the
> > top gear ratio is still going to be 1:1, see "overdrive" comments
> > below-
>
> I'll admit most problems were related to the installer (me). I've
> learned a lot in the past 12 years, so I think this time it would be
> much better. Main problem was I still couldn't cruise at 60, since I
> didn't change the gears. Back then I thought the V6 would give me
> higher RPMs, like 6000 instead of 3000 (double my speed). Dumb
> mistake.
>
> > The D18 xfer case is plenty strong for what you're talking about. the
> > only problem with them is that the intermediate shaft needle bearings
> > tend to chew up the shaft after about 30K miles, a hardened
> > intermediate shaft from Novak fixes that quite nicely.
>
> Good to know, I'll check that out before I give the go ahead to the
> rebuild guy. He probably knows about these parts also, so I'll see
> what he thinks.
>
> > The T90 if rebuilt properly should last as well as anything else you
> > can stick in there. An auto tranny is going to give you grief with a
> > ridulously short rear drive shaft & depending on the transfer case may
> > need a two piece "Commando" style front shaft to get around it.
> > Unless you really hate shifting or really need to creep over big rocks
> > I'd pass on it.
>
> I'll just have to measure since I'm getting conflicting info from each
> person I ask. I think a lot of people are trying to put the auto in
> the newer rigs with the straight xfer case, and I've heard they fit
> better with my offset case because the rear output is lower. Seems
> like most people think the T90, along with other stock jeep trannys are
> all weak. I guess even the stock trannys with the stock V6, from the
> factory, broke a lot.
>
> > Likewise the Dana 25/41 axles should also hold up fine for your use,
> > everbody rags on the weak axle shafts but they are in fact the same
> > piece as found in early 44s. As for the ring swap get a Warn/Saturn
> > overdrive instead, you get the best of both worlds for a lot less
> > money :).
>
> If my axles were in good shape I'd think more about keeping them. I
> think the overdrive is a 30% increase, which is just what I need:
>
> 60 * 70% = 42 (so I'd be able to go 60 with the same RPMs I currently
> get at 42, which 42 is around 2200 RPMs if I remember correctly
> (haven't had the tach on for a while))
>
> I'll check that site, but I know overdrives aren't cheap.
>
> > Not to dissparge the level of expertise here but I would suggest you
> > also solicit opinions on the ****** Tech list-
> >
> > http://autos.groups.yahoo.com/group/WillysTech/
>
> Hadn't seen this one yet, thanks.
>
> > Good luck which ever way you decide to go-
>
> Thanks!
>

 

Overdrives on that site are about half the price I thought they would
be. Nice! However, they are only a 25% difference, and not 30% like I
had thought. That would still get me to about what I wanted, but
around 2600-2800 RPMs instead of 2200 which I think would be optimal
for engine life. On the other hand, if I change from 5.38 gears to
3.73 gears, that is a 31% difference, which sounds better to me.

Haven't priced the new front and rear vs.the overdrives, so not sure if
it is going to be worth it yet. The overdrive would be less work, and
probably less $$$, but then I am stuck with the old style front/rear
which you can't get upgrade parts for.

eselk@surfbest.net wrote:
> If my axles were in good shape I'd think more about keeping them. I
> think the overdrive is a 30% increase, which is just what I need:
>
> 60 * 70% = 42 (so I'd be able to go 60 with the same RPMs I currently
> get at 42, which 42 is around 2200 RPMs if I remember correctly
> (haven't had the tach on for a while))

 

Overdrives on that site are about half the price I thought they would
be. Nice! However, they are only a 25% difference, and not 30% like I
had thought. That would still get me to about what I wanted, but
around 2600-2800 RPMs instead of 2200 which I think would be optimal
for engine life. On the other hand, if I change from 5.38 gears to
3.73 gears, that is a 31% difference, which sounds better to me.

Haven't priced the new front and rear vs.the overdrives, so not sure if
it is going to be worth it yet. The overdrive would be less work, and
probably less $$$, but then I am stuck with the old style front/rear
which you can't get upgrade parts for.

eselk@surfbest.net wrote:
> If my axles were in good shape I'd think more about keeping them. I
> think the overdrive is a 30% increase, which is just what I need:
>
> 60 * 70% = 42 (so I'd be able to go 60 with the same RPMs I currently
> get at 42, which 42 is around 2200 RPMs if I remember correctly
> (haven't had the tach on for a while))

 

Overdrives on that site are about half the price I thought they would
be. Nice! However, they are only a 25% difference, and not 30% like I
had thought. That would still get me to about what I wanted, but
around 2600-2800 RPMs instead of 2200 which I think would be optimal
for engine life. On the other hand, if I change from 5.38 gears to
3.73 gears, that is a 31% difference, which sounds better to me.

Haven't priced the new front and rear vs.the overdrives, so not sure if
it is going to be worth it yet. The overdrive would be less work, and
probably less $$$, but then I am stuck with the old style front/rear
which you can't get upgrade parts for.

eselk@surfbest.net wrote:
> If my axles were in good shape I'd think more about keeping them. I
> think the overdrive is a 30% increase, which is just what I need:
>
> 60 * 70% = 42 (so I'd be able to go 60 with the same RPMs I currently
> get at 42, which 42 is around 2200 RPMs if I remember correctly
> (haven't had the tach on for a while))

 

Yah, I think an OD tranny is a better design (although not as easy)
because your first gear (and all the others) are still as low as
always. With double, or more, HP that I'll get from going from the
L-head to a V6 (Buick or Chevy), I think I'll have at least the same
torque I have now even with a 30% gear difference. And I like going
slow off-road, so low-range is always an option. As long as I don't
end up with something that burns clutches in 1st gear when driving
around the city.

Earle Horton wrote:
> If you got a Buick V6 professionally race balanced and installed a different
> cam, I'll bet you could get 6,000 rpm out of it. ;^)
>
> Remember that while an overdrive increases road speed at a given engine rpm,
> it decreases torque at the rear wheels. The factory overdrive (fifth gear)
> in my 2.5 liter Wrangler is pretty much useless for that reason. So if you
> install an overdrive or regear, you will probably need to increase engine
> displacement to compensate.
>
> Earle
>

 

Yah, I think an OD tranny is a better design (although not as easy)
because your first gear (and all the others) are still as low as
always. With double, or more, HP that I'll get from going from the
L-head to a V6 (Buick or Chevy), I think I'll have at least the same
torque I have now even with a 30% gear difference. And I like going
slow off-road, so low-range is always an option. As long as I don't
end up with something that burns clutches in 1st gear when driving
around the city.

Earle Horton wrote:
> If you got a Buick V6 professionally race balanced and installed a different
> cam, I'll bet you could get 6,000 rpm out of it. ;^)
>
> Remember that while an overdrive increases road speed at a given engine rpm,
> it decreases torque at the rear wheels. The factory overdrive (fifth gear)
> in my 2.5 liter Wrangler is pretty much useless for that reason. So if you
> install an overdrive or regear, you will probably need to increase engine
> displacement to compensate.
>
> Earle
>

 

Yah, I think an OD tranny is a better design (although not as easy)
because your first gear (and all the others) are still as low as
always. With double, or more, HP that I'll get from going from the
L-head to a V6 (Buick or Chevy), I think I'll have at least the same
torque I have now even with a 30% gear difference. And I like going
slow off-road, so low-range is always an option. As long as I don't
end up with something that burns clutches in 1st gear when driving
around the city.

Earle Horton wrote:
> If you got a Buick V6 professionally race balanced and installed a different
> cam, I'll bet you could get 6,000 rpm out of it. ;^)
>
> Remember that while an overdrive increases road speed at a given engine rpm,
> it decreases torque at the rear wheels. The factory overdrive (fifth gear)
> in my 2.5 liter Wrangler is pretty much useless for that reason. So if you
> install an overdrive or regear, you will probably need to increase engine
> displacement to compensate.
>
> Earle
>

 

I looked at the TH350. That might be a really good option. According
to Novak's web-site, I might not even need to move my xfer case. Can
anyone confirm this? Which engine would I need to use? It isn't an OD
tranny, so unless I could build a V6 that would be happy (and not drink
too much) at 3600 RPM, I'd still need an OD unit or to change gears.

Earle Horton wrote:
> Advance Adapters has an article in their Jeep Conversion Manual on Saginaw
> steering conversions.
>
> Don't rule out the automatic, if it is what you really want, until you get
> the measurements on a TH350 and do the gear ratio engine speed math.
>
> It wouldn't hurt to cruise the used car lots where you live, and see what is
> available in a newer model. You could call it "research". Sometimes they
> have coffee and donuts.
>
> Earle

 

I looked at the TH350. That might be a really good option. According
to Novak's web-site, I might not even need to move my xfer case. Can
anyone confirm this? Which engine would I need to use? It isn't an OD
tranny, so unless I could build a V6 that would be happy (and not drink
too much) at 3600 RPM, I'd still need an OD unit or to change gears.

Earle Horton wrote:
> Advance Adapters has an article in their Jeep Conversion Manual on Saginaw
> steering conversions.
>
> Don't rule out the automatic, if it is what you really want, until you get
> the measurements on a TH350 and do the gear ratio engine speed math.
>
> It wouldn't hurt to cruise the used car lots where you live, and see what is
> available in a newer model. You could call it "research". Sometimes they
> have coffee and donuts.
>
> Earle

 

I looked at the TH350. That might be a really good option. According
to Novak's web-site, I might not even need to move my xfer case. Can
anyone confirm this? Which engine would I need to use? It isn't an OD
tranny, so unless I could build a V6 that would be happy (and not drink
too much) at 3600 RPM, I'd still need an OD unit or to change gears.

Earle Horton wrote:
> Advance Adapters has an article in their Jeep Conversion Manual on Saginaw
> steering conversions.
>
> Don't rule out the automatic, if it is what you really want, until you get
> the measurements on a TH350 and do the gear ratio engine speed math.
>
> It wouldn't hurt to cruise the used car lots where you live, and see what is
> available in a newer model. You could call it "research". Sometimes they
> have coffee and donuts.
>
> Earle