I just picked up a 82 chevy 3/4 ton camper special deluxe with the 6.2 in it. I got the exhaust all replaced, I notice a good vibration with nice reverb in the cab at idle, goes away once I am off and moving down the road, just happens at idle. Not a miss or anything like a dead cylinder, just acts like the exhaust is rigidly mounted to the frame, which it isnt. Also did GM use the 700r4 behind the 6.2 in 82 or its it a turbo 400? It shifts clean and smooth but I only count 3 shifts and with the 4:10 rear end she is really turning some rpms at 60 mph. Body is still solid for a rust belt truck and the under neath is super solid. Was the vibration damper the rubber issue version in all 6.2 years, this one doesnt look like it has the rubber core. Thanks Mike

I notice a good vibration with nice reverb in the cab at idle, goes away once I am off and moving down the road, just happens at idle. Not a miss or anything like a dead cylinder, just acts like the exhaust is rigidly mounted to the frame, which it isnt.

From what it sounds like, I have a similar vibration but it is defently from my exhaust. put my boot against it and it all goes away. engine mounting brackets maybe? Ive seen a vibrations on a 6.2 suburban because of that. noisy/vibrates at idle but pretty much gone when moving.

I just picked up a 82 chevy 3/4 ton camper special deluxe with the 6.2 in it. did GM use the 700r4 behind the 6.2 in 82 or its it a turbo 400? It shifts clean and smooth but I only count 3 shifts and with the 4:10 rear end she is really turning some rpms at 60 mph. Body is still solid for a rust belt truck and the under neath is super solid.

I think the 700R4's were available then for the 6.2, defently in 1983. Check the RPO codes in the glovebox. sometimes its listed something like "3spd auto trans" or "4spd auto trans w/over" Never seen it say "TH700R4/350/400" Sometimes its not listed at all. RPO codes are weird and what is/whats not listed is not always standard.
Check the transmisson pan. 700R4 is pretty square looking. 400 kinda looks like the state of texas.
On the transmisson, look for a vacuum modulator...looks like a cylinder shaped canister off the drivers side i think. vacuum lines on it. 350/400 had them, 700R4 had the throttle cable.
As an after thought, doesnt the dash gear selector tell you? 400 would be D-2-1 and 700R4 would be D-3-2-1 with "automatic overdrive" written over it, for that year I believe. if not a O will be around the D.

Some of that wont make sense if its been swapped with a different type at one time. the pan and modulator are giveaways.

My guess is that its a 400, for that kind of truck. you should be able to figure it out now at least.

Was the vibration damper the rubber issue version in all 6.2 years, this one doesnt look like it has the rubber core. Thanks Mike

I dont know of any changes to the harmonic balancer. Ive read if the rubbers gone or falling apart, its time to change.

The 6.2's did not suffer the rubber ring failure like the 6.5's, with their "spyder" design. The 6.2 was more like the gas engine. Just a rubber ring between the two pulley rings. Nothing was driven off the outside, rubber mounted part. Just off the center hub. I've only seen one fail since '82. Unfortunately, it broke the crank and block main web.

Ok, she as a turbo 400 by the looks of it, has the modulator on the side and only 1-2-D on the column shifter. If memory serves me correctly the T400 is a 3 spd transmission correct? once the pipes from the manifolds rot out, wont be long now they are pretty rusty and thin, I plan to go to a single 3" or 4" pipe instead of duels. I plan to leave her a NA diesel for now, unless I stumble on a banks system for a steal. Thanks Mike T

Ok, she as a turbo 400 by the looks of it, has the modulator on the side and only 1-2-D on the column shifter. If memory serves me correctly the T400 is a 3 spd transmission correct?

yes the TH400 is a 3spd auto. so is the TH350. the 400 is the heavier duty version and known to be a really stong long lasting one. the "D" just means direct drive. subsitute for a "3".

the 700R4 benefits is the overdrive and low first gear, but not as strong as a 400.

in case you were wondering about the gears:
400: 1st-2.48:1/2nd-1.48:1/3rd-1.00:1/R-2.08:1
700R4: 1st-3.06:1/2nd-1.62:1/3rd-1.00:1/4th-.70:1/R-2.29:1

once the pipes from the manifolds rot out, wont be long now they are pretty rusty and thin, I plan to go to a single 3" or 4" pipe instead of duels. I plan to leave her a NA diesel for now, unless I stumble on a banks system for a steal. Thanks Mike T

best to go duals with free flowing mufflers. 2.5" duals are less restrictive then single 3". add a crossover as well. just an opinion though.

The diesel mechanic I use worked for gm when the 6.2 was developed so he knows them like the back of his hand, just hard to get ahold of, he operates a on site vehicle maintance shop that comes out to your stranded big rig. He said to go with either duel 2.5 inch with a crossover or a single 3" with a straight thru muffler like the ones banks and others use, or a tractor muffler with the correct pipe size, ether would be better than the 2 1/4" stuff it has now, and will flow better. I prefer a single, cheaper to fab up, less to rust out up here in the rust belt, no good stainless shops around here! But for now both tail pipes are new as it one muffler so its good for atleast another year. Going to get the plates now and take the boat out afterwards, see how she does pullling it. Cheers Mike