Re: 1972 GMC 2500 6.2 Diesel
 

I’m sorry for my late reply, yes it still sounds like a diesel, especially since the engine bay has virtually no insulation. It is far more tolerable now in the cab since it dumps behind the axle. But when I drive by it still sounds like a train car full of doorknobs going over a cliff!

I had a problem getting it started the other day and that led to checking the block heaters - I have ordered new cords - as well as a new starter. The starter is pretty tired and so it runs the battery down which in turn heats that starter up. I’ve learned that for a diesel in particular it just isn’t a good idea to have a weak link in your starting system. The one I ordered is off of Amazon, it looks to be made in USA and has good reviews. I’ll post some more pics when it arrives, and a link.

I hate to think someone stole it but the decal on one of my dually hub covers went missing so I ordered another off of eBay, luckily it was cheap.

Truck also needs a rear main seal so I guess I will be doing that too!

The 51 chev is not mine, it’s a friends I just like how they look together.

Re: 1972 GMC 2500 6.2 Diesel
 

I used to have a connection with a diesel shop, for the small (one ton) vehicles we worked on at my work's shop.
He recommended to replace a gear drive starter with the older direct drive starter because the direct drive starters actually spin the engine faster gear drive type. We performed such a swap many times, and it did help...

Let me know if you have any trouble getting the block heater cords. I may have some spares. I'd have to see the ends of your old ones to know for sure.

Tail pipes couldn't hurt the exhaust tone...

At my previous job (school bus dealer). We had a customer complaining about engine noise. The bus was a front engine transit type bus, the engine bay is next to the driver, has a dog house you lift up to get to engine. Very difficult to work on...........
My boss googles around and found a company that made insulating materials (I do not remember brand...). We bought a small roll of one inch theick flexible dense foam with a thick foil backing that also reflected heat. We put it on the back side of the engine cover, and a couple of other small areas. It made a HUGE difference in the noise level. I think you could accomplish the same with your diesel...some how...wouldn't take a lot of $$$ or time...mostly thinging of where to install. I'd at least cover the underside of the hood...

Re: 1972 GMC 2500 6.2 Diesel
 

I did manage to find the block heater cords, and I am always looking for cheap sound deadening, I saw a thread where someone put something like that in the doors. I agree that I should be putting that under the hood. I wondering if it would help keep the sound down on the street, too, the hood itself vibrates pretty good with the engine running!

This past week I did replace the starter with this one, it claims to be completely new and not remanned, I guess we will see how it works.

Also replaced the rear main seal and oil pan seal. Had to jack the engine up to get at the oil pan seal. Just hoping to keep the mess on the street to a minimum.

I'm starting to wonder how many miles are on this engine, I wish there were options for rebuilding or replacing them but most people consider the 6.2 not worth working on.