Surburban Furnace Ills - HELP

[Cat]

Hi guys...

It's Cat. I need to repair my Suburban furnace. It's not working. What happens is this:
It starts up (ignites) and 10 to 30 seconds later, it dies. STOP!
It has been ascertained that it is due to the main "Mother Board" ("Circuit Board")...
I went to my friendly local RV dealer, and they gave me parts numbers...and costs...yikes!!!!
Then I called our Forum friend, Andy, who told me basically, that parts obtained cheaper are not always the best (who knew?). (In automobile 'spek' we call it "AFTER-MARKET PARTS')
....Not always a good deal.

Like Andy at Inland said, you can save a few bucks at the get-go---by buying an 'off-brand', and then be forced to spend BEAUCEAU bucks later because the cheaper one didn't properly fit with the 'stock parts'. (Should be no surprise.)
(THIS IS WELL KNOWN IN THE AUTO INDUSTRY)

I also got good advise from Andy, that taking the furnace apart (the "S" curve---between the fan and the combustion chamber---and giving it a little shake as it's removed (gently) can shake out close to a whole CUP of rust &/or other CR___ that's gotten into the chamber...which can reduce the efficiency of the furnace (to have the combustion chamber's volume so reduced). He also suggests I do this prior to installing a new circuit board & he says that my '83 (shhhhhhhhh! it's 'really' an '81..right?) is really worth repairing,,,since the original parts & appliances are so well-made that they are worth keeping, rather than replacing.
So, here's what my plan is:
1. Get a space heater to keep Bear warm while the furnace is down.(*see below for question.);
2. Pull the furnace OUT ("S" curve first); the 'mother board' is already out; the 'ignitor plate (with elemments) is also out---and the gasket is being ordered and replaced (after the back of the plate has been thoroughly cleaned with 'gasoline');
3. Thoroughly clean the whole furnace...with gasoline & a toothbrush...and reassemble;
4. Replace the main "circuit board" (Mother Board);
5. Replace the Ignitor plate with new gasket;
6. Put the whole furnace back together and start up.

DOES ANYONE HAVE ANY OTHER 'WORDS OF WISDOM' TO IMPART TO ME??? (to
give me more advise....?)
DOES ANYONE HAVE A MAIN "SUBURBAN" CIRCUIT BOARD FOR SALE?? I'd actually rather buy a brand new one ($143.00 + shipping)...but I've heard of those who have either totalled their A/S, or are parting them out for one reason or another...and I'd purchase one that was a Suburban that was in good working order if the price was low enough.

ANY SUGGESTIONS ON A GOOD SPACE-HEATER TO PURCHASE? I DON'T MIND SPENDING A GOODLY AMOUNT ($70 to $100)...AS LONG AS IT'S ONE I CAN USE AGAIN AND AGAIN---TO SUPPLEMENT THE PROPANE. (I do want to buy a space heater that is ELECTRIC.)

I will apppreciate all advise
and will be very grateful for any offers to sell a 'second-hand' part mentioned above.

...........Cat