Hey Jay,
I'm new to the forum but have been trying to fix my suburban with some other issues and dealt with compression and vacuum leak issues. Something I did after replacing seals was to use engine restorer in the oil to help clean things up and increase compression. I'm wondering if that would help your compression reduce the output of hydrocarbons. Link to the product below.
https://www.oreillyauto.com/detail/c...0-suburban-4wd

 

I've never tried any products like that, but that might work or they wouldn't sell it. In looking into high hydrocarbons, I think I need to find TDC, and see where the distributor is pointing. I bought a new distributor that has no Vacuum advance, as they said between 85-87 some had vac advances, and some didn't, but must have the ECM for the non vacuum advance type. If the dampner has spun I can rescribe the TDC MARK and try that. I have been told 2 different timing marks for this year, as the directions under the hood say 8° Btdc, but on a non, vacuum style, I am told to set it at 0. I am going to have a friend help me to get that right, as too much advance on timing can increase hydrocarbons. That removing the distributor, if I do that, will help me get to the rear rail, to try to seal it up., as it may be leaking there.
i finished the flowkooler 460 ford BB water pump job, but did NOT install the double roller chain. I never did a pump on a BB ford, and it had more crap to remove than I expected. Put in a double water pump gasket for impeller clearance for the flowkooler and a 180 robertshaw thermostat. Snapped off a thermostat housing bolt, as they were tighter than a bulls *** in fly time. Luckily I had enough threads to put on a nut, and welded the nut onto what was left, and got it out. Forgot where the brackets went, but found a breakdown photo, and held up the power steering pump with a round extention chord , as I took all that crap off .....probably shouldnt have, but wanted to clean it all up. I need to go back east to Pa. For a trip, and at 5.00 a gallon and the truck gets 6 mpg, I am not looking fwd to the high prices of Bidens gas war against drivers. Anyway back to the suburban, I have a idle miss, but still doesnt idle right ,but runs good advanced, although, retarding it, doesnt get good mileage, but might pass . I GUESS I have a week to take it in free for a second test. I may run a compression test. On the ramcharger that was stalling out, I rebuilt the holley 2brl , fixed all vacuum lines, and put in 2 new fusible links. It runs a lot better, and gets better mileage, but still needs the ball joints replaced. I might try your additive, but will try this other stuff first. It could use a valve job, , but no time right now. The carbon monoxide levels are good, so , studying up on high hydrocarbon solutions. Might bypass cruise control vac booster by running the 2 hoses together.that go to it, as it doesn't work, so that might have a
eak. I'll keep you informed, and thanks again for all suggestions.