Overdrive or don't worry about it? !

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MrJLR

MrJLR

Built, not bought
FABO Gold Member
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Menifee, California
Good morning everyone!
Some of you might know I'm doing a big build on my 1968 Barracuda. .....currently having a 318/392 stroker built over at IMM Engines. .....

So, Freeway driving. .....
I'm seriously considering an overdrive for cruising the highway.
Or, do I really need one?

Only really want to freeway drive a few times a year.....maybe 100 - 200 mile trip or two (each way) a year.....the rest of the time would just be romping around town.

When I'm on the freeway I don't want to limit myself to 55-60mph....I'd get run over here in Southern California! It would be more like 70-75mph.

So, do I really need to worry about an overdrive?
Would driving at 3000 - 3500 RPM a few times a year really be all that hard on my engine?

I'm probably way over thinking this but I value all your opinions.

Gratuitous photo of said 'Cuda

image000001(8).jpg


Jeff
 
Oh, I will be getting larger diameter wheels and tires. ....
That should help with my final drive ratio. .....

Jeff
 
IIRC, you had a thread about going all out on the rebuild, I say an overdrive unit would be a plus.

If you intend to keep the car, how are you gonna like those RPM's in 10 years, 20?

Best of both worlds, IMO, keep the performance where you want it, and then sit back and relax on a long trip. Win/win!
 
Bad Sport said:
IIRC, you had a thread about going all out on the rebuild, I say an overdrive unit would be a plus.

If you intend to keep the car, how are you gonna like those RPM's in 10 years, 20?

Best of both worlds, IMO, keep the performance where you want it, and then sit back and relax on a long trip. Win/win!
Click to expand...
Ok, that said, 2004R or Gear Vendors? !

Jeff
 
Pro's and con's
Gear Vendors can be a PITA to install. ...floor pan fitment etc, but I keep my 727.

2004R is an all in one and no throttle pressure linkage to mess with, but no idea about how much is involved in the install and what about my stock shifter I love so much?

Jeff
 
My uncle use to have two sets of sure grips one highway gears and the other like a set of 4.10 and when he'd go on long trip just swap in the highway gears.
 
How about buying a second pig with a 2.73 or so in it. Then switch them out for your long drive, and switch again when you get home. Hi RPM drone will bother you on a long trip. @MrJLR

Looks like @273 and I came up with this at the same time - and he’s a faster typer! :lol:
 
68gtxman said:
How about buying a second pig with a 2.73 or so in it. Then switch them out for your long drive, and switch again when you get home. Hi RPM drone will bother you on a long trip. @MrJLR
Click to expand...
Thing is, I want to build this car one last time and stop most of the heavy work.....I've got a bad back and just can't see swapping rear ends and engines etc much more as I get older....

Jeff
 
273 said:
What about a gearvendor unit ?
Click to expand...
I mentioned that above. ....just a little worried about fitment issues....floor pan mods etc....
Aren't they a pain to install in these little a-bodies?

Jeff
 
MrJLR said:
I mentioned that above. ....just a little worried about fitment issues....floor pan mods etc....
Aren't they a pain to install in these little a-bodies?

Jeff
Click to expand...

Not sure ask AJ/FormS I'm sure he's running one
 
MrJLR said:
I mentioned that above. ....just a little worried about fitment issues....floor pan mods etc....
Aren't they a pain to install in these little a-bodies?

Jeff
Click to expand...

gear vendors goes in an abody easily. just a couple dings with a ballpeen hammer is all a friend needed to install in his dart. the GV is pretty much bullet proof too.. most of the drag week cars are running them.. they will turn a 3.55 gear into something like a 2.76.... the 200r has a better first gear and OD ratio but is also a ton more work from what i understand.. pretty sure you have to do some cutting on the cross member.

and i agree. screw switching a center section just to do a road trip..lol
 
Have you considered 3:23s? I've had my car a long time and the way I drive and what I want have changed considerably.
I recently changed from 3:55s and there is a noticeable difference in low end performance but the trade off for the lower rpm at cruising speed suits me now.
 
Well, looks like I'll be wanting an overdrive for sure....

Guess I need to research the Gear Vendors a whole lot now...

Jeff
 
MrJLR said:
Good morning everyone!
Some of you might know I'm doing a big build on my 1968 Barracuda. .....currently having a 318/392 stroker built over at IMM Engines. .....

So, Freeway driving. .....
I'm seriously considering an overdrive for cruising the highway.
Or, do I really need one?

Only really want to freeway drive a few times a year.....maybe 100 - 200 mile trip or two (each way) a year.....the rest of the time would just be romping around town.

When I'm on the freeway I don't want to limit myself to 55-60mph....I'd get run over here in Southern California! It would be more like 70-75mph.

So, do I really need to worry about an overdrive?
Would driving at 3000 - 3500 RPM a few times a year really be all that hard on my engine?

I'm probably way over thinking this but I value all your opinions.

Gratuitous photo of said 'Cuda

View attachment 1715741543

Jeff
Click to expand...
If you have the coin I would do it with out a thought.
904 with a lock up convertor - 42 RE ?
 
Very interested in that 392 build.

Have you considered a second set of rear wheels and tires to change the effective final drive?

Initial investment is not terrible compared to a second 8 3/4 chunk, but labor savings over time sure would add up.

I believe 2 inches in diameter makes a noticeable difference.
 
I really don't see you as a 1/4 mile racer (or at least on this site). Here is something to consider. Your 390 will have a ton more bottom end torque than what you have now. Perhaps you could drop down to 2.94's and still be plenty happy with bottom end and you'd cruise 70 mph without a problem. Just a thought. OD is a great way to go....
 
318willrun said:
I really don't see you as a 1/4 mile racer (or at least on this site). Here is something to consider. Your 390 will have a ton more bottom end torque than what you have now. Perhaps you could drop down to 2.94's and still be plenty happy with bottom end and you'd cruise 70 mph without a problem. Just a thought. OD is a great way to go....
Click to expand...
That's certainly a consideration. .....
Would the 2:94 really be a big enough difference on the freeway from my 3:55 ???

Jeff
 
MrJLR said:
That's certainly a consideration. .....
Would the 2:94 really be a big enough difference on the freeway from my 3:55 ???

Jeff
Click to expand...
I just pulled 2.94's out of my Duster, but I loved them for all around use. I cut 1.8 60 ft times with stock converter, I could cruise 60 mph all relaxed (70 would be no problem) and the car ran really cool even on hot days.
 
I would say OD based on OP comment of bad back and not wanting to do the work at changing the center section. Really takes less than an hour. I am running 3.91 typically. Just picked up a cheap ($150) 2.94 open 489 rear end (bbody) threw a spool ($90 from Dr Diff or Quick Performance) in it for the drive up to Mopars in the Park. 5 hours each way. 2500 at 70mph. Was at 3000 at 60mph. Totally a different car on freeway now.
 
My favorite part of having an OD trans is the fact that it's so much quieter on the 70mph highway cruise. I still run my 4.10 gear but it is a sweetheart on the highway as well. If you have the funds, a GV would be great. I have an A500 and it fits my needs too.

Cley
 
Also, a gear vender OD would add a lot of value to the car because they are respected. I know you aren't looking at resale and you are building a keeper. Just say'n...
 
26" tire:

3.55 @ 70mph = 3250 RPM
2.94 @ 70mph = 2670 RPM

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28" tire:

3.55 @ 70mph = 3000 RPM
2.94 @ 70mph = 2500 RPM





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