High Class Problem

[AndyMoriarty]

I could use some advice/opinions to help me made a decision on a built 700R4 versus a Gear Vendor Overdrive bolted to a TH400. I have a 69 GMC with a 502 Ramjet (510hp/560torque) mated to a TH400 into a 12 bolt posi with 4.11 gears. I intend to take it on the long haul Power Tour next year and desperately need an overdrive gear. The truck is not raced but driven hard between lights. My most important goals are to get a highway cruising gear with very high reliability. I like the idea of simply installing a Monster 700R4 but I am concerned about its reliability versus the much more expensive Gear Vendor Overdrive. All thoughts and opinions on thye pros and cons are appreciated as I need to make a decision.

Best Regards and thanks.

Andy

[jocko]

Can't beat GV O/U drive, but, as you pointed out, they are rather expensive. Since you describe the o/d for the highway gearing aspect alone, you'd be spending all the money on the g/v unit and not likely using any of it's gear splitting capability in the lower gears, just in high gear. Even if you have a monster big block with tons o torque, all that matters is how you drive it. If you aren't doing burnouts, then the 700 would live behind your 502 just fine. But - since you DO have a 502 in front of it, my initial tendency to go for the 700R4 is a bit tamped down in this case. If you have the $ to spare (ha) for the gn unit, I'd go that route just because of the excess amount of torque you COULD apply to the driveline. My 2c. The gv unit is pretty indestructible.

[AndyMoriarty]

Thank You!

[Fitz]

Originally Posted by AndyMoriarty

I could use some advice/opinions to help me made a decision on a built 700R4 versus a Gear Vendor Overdrive bolted to a TH400. I have a 69 GMC with a 502 Ramjet (510hp/560torque) mated to a TH400 into a 12 bolt posi with 4.11 gears. I intend to take it on the long haul Power Tour next year and desperately need an overdrive gear. The truck is not raced but driven hard between lights. My most important goals are to get a highway cruising gear with very high reliability. I like the idea of simply installing a Monster 700R4 but I am concerned about its reliability versus the much more expensive Gear Vendor Overdrive. All thoughts and opinions on thye pros and cons are appreciated as I need to make a decision.

Best Regards and thanks.

Andy

Andy:

The answer to your question lies in the motor you are running. I run a Gear Vendors overdrive in back of a built turbo 400 instead of a 700R4 because the 400-GV combo is good to 900 ft-Lbs of torque and 1000HP. The 700R4 can take a smaller motor but my ZZ572 will turn it into a grenade the first time I launch the truck. Your 502 will likely do the same. When I built my truck I went to see John Winters ( my neighbor) at JW Performance Transmissions and he did say for an engine with less torque, the 700R4 was OK but with the higher output of the 502/572 he could not build one strong enough to live very long. So, I took his advice.
Fitz

[AndyMoriarty]

Thank you !!

[cleszkie]

I have a Gear Vendors unit behind my NP205 transfer case on my Blazer. Yes they can be spendy, but are worth every penny in my opinion. Strong as nails, very easy to maintain, very easy to install, excellent customer service and support, and they really maintain their resale value. Just figure in the cost of a couple of standard rebuilds of the 700R over a period of 10 to 15 years of normal use when comparing to the cost os a single Gear Vendors unit. If maintained properly,the Gear Vendors unit will easilly last 10 to 15 years and longer without needing a rebuild. You spend the money up front, but save in the long run.

[CG]

Although Im not going with this combo any more, I did a ton of research first. Caddy 500, turbo 400 and a gear vendors. Everything I came up with pointed me in this direction over late model OD trannys. So I had TCI build me a nice turbo 400 and purchased the GV direct.

Things change with long (forever lol) term projects and I ended up selling the GV, and the 500 and 400 sit all snuggly in my shop =)

[68shortfleet]

Would it be worth considering a 4L80E? Overdrive transmission that came factory behind big blocks.

Just a thought..

[leftybass209]

The 700r4/4l60e has too low of a 1st gear (3.06) to be mated with 4.11's in the rear with that much power.

The 700r4/4l60 can be built to handle that much power, but I don't think it's cost effective.

You may want to look into a 2004r, or 4l80 trans. Those can also be built to handle the power (4l80 much better than a 2004r), but have a much more usable 1st gear.

Nothing wrong with gear vendors at all, other than the price and extra weight/space it takes up, which usually is never a problem, but is worth noting.

Gear vendors has some good info on their site.

[Fitz]

Originally Posted by 68shortfleet

Would it be worth considering a 4L80E? Overdrive transmission that came factory behind big blocks.

Just a thought..

The 4L80E started production in 1991. The 454 was the only available 'big block' at the time. Stats by year for the 454 show that it was pretty 'anemic' when compared to the 502 Andy plans to use.

1988–1995 230 hp (170 kW) @ 3600 RPM 385 lb·ft (522 N·m) @ 1600 RPM
1996–2000 290 hp (220 kW) @ 4000 RPM 410 lb·ft (560 N·m) @ 3200 RPM
1991–1993 255 hp (190 kW) @ 4000 RPM 405 lb·ft (549 N·m) @ 2400 RPM 454SS

[Fasglas]

The bad thing about the 4L80e is figuring out how you want to control it. Some of the electronic controllers can be pretty expensive.
But if you've got the bucks I think the 4L80e is a good choice for the street/strip because it's basically a Turbo 400 with overdrive. For me the bonus the 4L80e would give you over a Gear Vendors is with the 4L80e you get a lock up converter for the highway. When the converter is locked it will help with gas mileage, help the motor last longer, and the transmission will run cooler.
One of the coolest things about having a lock up converter is you could run a loose converter for those hard launches and when you hit the highway and the converter is locked.....BAM!.....the loose converter is GONE....because the converter is locked.

[davepl]

My built 200-4R lived forever behind a ZZ502 with slicks in a 4300 pound car turning 12s.

In my case I opted not to run a lockup converter because I was told that the clutches are so small in them that you'd rip it out pretty easily. I'd imagine the 4L80E lockups are much tougher.