4.8 4l60e vs 4 or 5spd

[JPsChevy]

I'm looking at buying a 99' 4.8l engine, I would love to stay with a manual transmission but i want something that will run down the highway and still get in the 20's cruising. So I have a few direct questions if anyone could help me out.

Is anyone running an m20 or m21?

Whats the 5spd that came with a 4.8l? Is anyone running one?

What crossmember is used?

Do i need to install a high hump?

[PGSigns]

Hopefully this will get moved tot he LS swap section. You will get a lot more exposure and answer over there.
Jimmy

[JPsChevy]

I'm hoping it does, that's where I originally thought I posted.

[68Stepbed]

I believe the manual trans used with the 4.8 is the NV3500. They're pretty decent as long as you're not planning to really beat on them. You'll have to search to find them, though. Apparently, Americans have become to lazy to shift their own gears anymore, so GM didn't build very many.

[yossarian19]

Yes, I think the 5 speed is a NV3500. It's good to around 300 ft-lbs. Not much else to say about it except that it's a PITA to rebuild one, from what I've read.
The big advantage of a NV3500 vs a M2x 4-speed is the overdrive, of course.
Without overdrive the 4.8 won't be making enough torque to get any performance *and* run 70+ mph at a cruising RPM. You'd have to pick one. I wouldn't want to run the 4.8 without overdrive and steeper gears in back, it would be kind of a let-down in a hobby truck.
I have a 2003 4.8 + 4L60e and 4.11 gears in back of my '57 longbed. It's fun and the overdrive lets it loaf on the highway. When it drops to third it takes off and makes you smile.

[elf w/capital T]

I've got a NV3500 behind my 4.8l its not a track truck by any means but being out in NC and cruising at 60 mph or even 70...that 5th gear ratio is amazing!

[elf w/capital T]

i cut out my floor and put a high hump.

made my own crossmember to support the nv3500, and it came out of a 92-93 Silverado.

hydraulic clutch is nice and smooth

had to buy special pilot pushing for input shaft but worth the hassle, can look up part number if needed, and flywheel and clutch were for a 4.8l motor

[JPsChevy]

Originally Posted by elf w/capital T

i cut out my floor and put a high hump.

made my own crossmember to support the nv3500, and it came out of a 92-93 Silverado.

hydraulic clutch is nice and smooth

had to buy special pilot pushing for input shaft but worth the hassle, can look up part number if needed, and flywheel and clutch were for a 4.8l motor

I'm going to try and run the low hump, I bought complete parts 06 with nv3500, if your running the new style nv3500 can you show me how you did your clutch to push the master cyl.

[solidaxel]

I have and drive manual 4 and 5 speed Muncie M20 and Tremac TKO600 and 4L60E
and have for many years........ no question the 4L60E is the only to go

[elf w/capital T]

I used allllmost the same ideas he did in post #16...

Just search nv3500 in the forum man, im at work and dont have all my photos.

I'll try and get them

[72blu]

Hi there, I recently put in a 2002 6.0l in my truck with a M22 behind it, I did not need to install a high hump the clearance was more than enough with the low hump floor. For crossmember I used this unit that I got from summit. I had to drill new holes in the frame, but other than that a perfect fit. https://www.summitracing.com/int/par...9427/overview/

[downeyballz]

Im running a late model nv3500 in my 1966 k10. great trans and holds up well behind my 292 inline 6. I also swapped in a hurst shifter and recommend it. I used a stock hydro internal slave cylinder and a 3/4" wildwood master cylinder with a stainless line between the two.