Converting 2WD Heat Stove to 4WD

[IronCanine]

Just what the world needs now...another heat stove thread. Not even my first . But I've thought for a while you could make a 4WD heat stove from a 2WD one, so tonight I put it to the test.

I had three examples in the old basement, none of which were particularly outstanding by themselves...two were pretty crummy. One was a 2WD with the rearward down pipe bend. The other was was a 4WD. The third is I believe a 4WD example, but without the aft cutout. All are non-A.I.R. versions. Neither of the two 4WD heat stoves ended at the same spot.

I have often wondered if they only stamped 2WD stoves and then just cut them. I have seen 4WD versions that were cut with an upper and lower "tail", or just an upper "tail" as pictured here. Though I can't be sure than mine hasn't just broken. I assume this cutout is clearance for a 4WD dipstick.

There are two half circles on the inner aspect that I used as a reference. Two pics show this point compared between the 2WD version and one of the 4WD versions.

Here are some additional links for the curious...even one to a reproduction heat stove for 76-80 Corvettes which is similar and probably workable for us:

https://67-72chevytrucks.com/vboard/...d.php?t=786952

http://67-72chevytrucks.com/vboard/s...d.php?t=115144

https://www.southerncarparts.com/c3-...gaAr5uEALw_wcB

[IronCanine]

Here are a few more pics of the "cut" level on the two 4WD versions. The level varied a bit side to side on the rusty one, and the other while pretty level was cut much shorter.

[IronCanine]

The process was pretty simple. I just had to work out the dings in the 2WD version and then cut the length to fit. And finally a little massaging of the bottom edge for shape.

I think it's a nice option since these things are so hard to come by...and there are quite a few more 2WD examples out there.

I will probably cut the back out as well, but since once it's cut it's gone, I thought I'd wait to pull the trigger on that. I might learn something in the meantime that changes my mind. ;p

[IronCanine]

Finally...these were likely black from the factory. I didn't know that six years ago when I did the Blazer. In hindsight, I still think the silver looks better though. Below is the 80 mile 70 C10 that you've all seen. And it's still the best reference I know of for factory finish on this part.

[davischevy]

Good info. I was wondering today if I was going to go back and paint mine black.

[IronCanine]

Just in case what your Monday night was missing was a couple of posts on a 4x4 heat stove. Picked this up at a swap meet a week or so ago from Woody (SouthernParts). Couldn't resist it as a reference piece. The back is in decent shape and even though it has the open end, it isn't missing any metal.

Note the finish on the backing plate. It's bare, save for some exhaust soot and dirt. Of course the paint could have come off cleanly from the heat but there is no trace and the metal is very clean. It's a finish like that that led me to ceramic coat one of these silver previously.

[DeadheadNM]

Brilliant. What tool did you use to make the cut?

[IronCanine]

Originally Posted by DeadheadNM

Brilliant. What tool did you use to make the cut?

Tin snips worked great. Then I dressed it a bit with an angle grinder.

[DeadheadNM]

Here’s a 4wd example, as found.

[IronCanine]

Thanks for posting Pete. Back looks pretty clean on that one too. Nice to get an A.I.R. example as well. I'd like to convince myself that some of those came out of the factory raw. Esthetically, I just like the look better.

[DeadheadNM]

Fun thread. Just a thought - it seems like more stoves have accommodations for the AIR injection tubes than there are AIR 4wds. Is it possible that some non-AIR K- truck V8s received stoves with holes for the tubes? I’ll dig to see if I can find any part numbers.

[IronCanine]

What about the Vettes? I've wondered if all the center dump heat stoves floating around were off 4x4s to begin with. Looks like the inlet is different on the 350 corvettes...but very similar. Nonetheless, it makes sense to me that some trucks without A.I.R. left the factory with heat stove that had holes.

Thought I'd search out some NOS examples from GM cars of the era to check finishes. Wouldn't you know it I got both. First is a Camaro, second is a C3 vette and the last one (dressed in black) is a Chevelle/El Camino big block (68-72) which is currently on eBay for $3500.00

[BigBird05]

I worked in a chevy dealership in 1972 and don't remember seeing any paint on the shields in the trucks. Then I went to work in a GM parts warehouse and most of the metal parts were painted with bonderite to prevent them from rusting. GM replacement parts do not come from the factory where they assemble the vehicles, they come straight from the venders. The factory orders are always filled before the parts warehouse orders. That is why there is sometimes such a long wait for current model replacement parts.

[IronCanine]

Originally Posted by BigBird05

I worked in a chevy dealership in 1972 and don't remember seeing any paint on the shields in the trucks. Then I went to work in a GM parts warehouse and most of the metal parts were painted with bonderite to prevent them from rusting. GM replacement parts do not come from the factory where they assemble the vehicles, they come straight from the venders. The factory orders are always filled before the parts warehouse orders. That is why there is sometimes such a long wait for current model replacement parts.

Thanks BigBird05. Finishes on a part like this are difficult...since they almost immediately rust and there don't seem to be any period color pics of new engine bays. The aforementioned 80-mile C10 is the best I have so far...and it just "looks" painted in the pic. I appreciate you taking time to share. Hopefully others will chime in.

[davischevy]

This is the heat shield on my 56,000 mile 1972 C10. The silver finish on the back pieces is what caused me to finish the shields in silver for the last 35 years.

The front piece on this one appears to have been painted or unfinished, but the rear is silver, maybe galvanized, as evidenced in th second shot.

[IronCanine]

Makes sense to me Larry. Thanks for posting.

[72Cheyenne454]

The one owner, 60,000 orig mile 1972 K20 I restored had air injection holes in the exhaust tin even though the truck never had, or was it required to have an air pump.

Here's a couple pics. I'm sure you'll notice it has an incorrect exhaust manifold on it in these pics. When I bought the truck the drivers side manifold was cracked, so I swapped it out for one I had laying around the garage.

I just remembered that after I had the exhaust tin blasted at the time of restoration, the inner tin portion (the piece between the manifold and head that the outer tin fastens to) appeared to be plated. It came back from blast with a silver, cad plating look to it. Almost looked like aluminum, or galvanized. I tried to find a pic of it with no luck.

[cericd]

Thought I'd add these pics I found online of a NOS heat stove P/N 3982954 which is also finished in black.

[IronCanine]

What a great pic. Thanks Chris.

[1970cstblazer]

Thank you for the pic. That's the way I restored mine, with the satin black outer and bright plated inner. I was going by the very low mile 1970 that has been pictured here in the past.

[54blackhornet]

I noticed in a few photos the flexible oil dipstick ? The one in my pretty original 71 307 with power brakes has it sticking straight up ? Also has the oil fill pipe , you have to be Houdini to get it out, nearly impossible to reinsert.