Looking for transmission advise.

Ok here goes again. I had such success with other posters helping on my engine problems, I was looking to see what everyone's opinions on transmission options are.

I have been doing some research for the past few months and have narrowed my selection down to the Tremec TKO 500 5-Speed Transmission
Application: GM
Input Shaft: 1-1/8 in. 26-Spline
Torque Rating: 500 ft.-lbs.
3.27 1st Gear
1.98 2nd Gear
1.34 3rd Gear
1.00 4th Gear
0.68 5th Gear
3.00 Reverse

I believe this trans is going to hold up to what I ask of it mostly cruising and ocational heavy load hauling of about 9000LBS for a short distance. I was wondering if there is others out there that have this trans or a similar rig that they could shed some input on what they find is best of its application.

Should I go twin disk clutch or regular?

Currently my at 60mph I am turning at 3000RPM + its working the motor hard for nothing and drinking the fuel like no tomorrow so with the 32% gearing increase with an overdrive tans I think this is going to be a huge benefit for my cursing nights.

I know its a large undertaking to convert a turbo hydro 400 truck into a manual 5 speed but it's a totally custom truck as it is and really want to add some fun to it with a stick shift.

I have a mild built sbc in an 1981 Chev 1 ton chassis and a custom 1950 cab mounted to it as a work truck. Been a few year build constantly upgrading but here is where I am at now.
1981 sbc stock bore stock crank 16000original miles rebuilt it because as everyone knows bad year for camshaft.
Put new rings bearings honed cylinders
comp cam110 degree normal lift longer duration cam
Double roller chain stock pin on cam gear
New jegs stock length pushrods
New roller rocker stock ratio valve train
New jegs 2.02 aluminum heads
New champion plugs
New spark wires
new hei distributor
New680 quick fuel vacuum second
Jegs duel plain high rise intake
All brand new gaskets
Custom 1 5/8 right to 3 inch no restrictions stack mufflers
Turbo 400 trans
4.10 rear gear

If anyone else out there has done a similar conversion and has another trans option I should be investigating please let me know.

I would think that'll be a fine choice. Especially for those "Cursing Nights"... LOL

I don't see a need for the double disc clutch setup. HTH

Personally, I would look at the TKO 600. With the 4.10 rearend, I wonder if you will really need the 3.27 first gear for occasional towing, unless you have to start on a hill.

I was told that the first gear set is the only real difference between the 500 and 600. The 3.27 gear set is weaker than the 2.87 set and reduces the overall torque rating of the trans. The 3.27/4.10 combo is going to be like a grandma first gear setup and I wonder just how much everyday use you'll get out of it. Just me thinking out loud.

It's not nearly the same, but in my '33 coupe I looked at the TKO 500, but with my engine putting out 475 foot pounds of torque I opted for the TKO 600 for a bit more cushion. My car's light, but I felt better not being right up against the torque rating. I went with a single disk clutch and haven't seen any issues.
On your cruise (curse) efficiency, it's going to depend a lot on your torque curve. I've got 4:10 rear gears too, and my cruise is 1995 at 70mph in 5th on 31" tall tires. My torque curve climbs steep from the idle range, rolling over and staying almost flat from 2000 out to 6000rpm, so the OD ratio is a great fit for me.
My first gear is very short, and I'm not near quick enough for a WOT launch in 1st, grabbing second before hitting the rev limiter. With the 4:10's and tall tires the acceleration is wicked, and the cruise is mellow. Like Mike said, I think you ought to look at the TKO 600 too.