Various stuff on '79 K5

I have a '79 K5 Blazer I bought about 6 months ago, it runs good, just a few minor issues I want to deal with.

This truck was born with a 305 engine in it. It now has a 350 with rv cam. which lead to the following problems:

  1. vacuum operated heat riser valve. This is currently connected directly to manifold vacuum instead of the tvs. Does the vacuum hold this valve open or closed? My stupid hanes manual has a typo in it that basically states that the vacuum both opens and closes the valve. I've tried both positions, but there dosen't seem to be much of a difference.

  1. throttle valve cable. It is an inch too short to fit on the throttle lever. Do these things come in different lengths, or do they have different brackets for different engine/ carb configurations? (I have a quadrajet 4mv.) I'm thinking I'll just hack the bracket.

It burns oil on startup, much more so when cold, but it clears up fairly quickly. Is that usually valve guides, rings, or a combination of both?

What type of oil is best? I used 5w30 in the winter, 10w30 for summer. or should 5w30 year round?

The transfer case is a np203, but the front axle has locking hubs. I'm not sure weather the hubs were installed in order to run in 2wd with the tcase in hi-loc or weather the entire front axle was swapped. I've read that the locking mechanism on the np203 was weak, so I've just been driving it in hi. It is hard to shift into the "loc" positions. Is that a sign of trouble to come, or is it more likeley the linkages?

Lastly, What guage sheet metal is used on the chevy trucks? I'm going to replace the rockers, and rear fender sections, but there are couple of places where I could just weld some paches in.

thanks in advance,

-Chris

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Christopher
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It help pull choke off on start, not close it for manifold vacum can work, it may need tweaking though

Yes cables com in different lenghts and 4bbl needs longer one

Chevys are know for valve guide seal issues, they are not hard to replace, I would check that first

Do not use 5w30 in that old engine as it is aggrevatting oil consumption. Run 10w30 even in winter and use 15w40 if it get real hot in summer and it will reduce consumptoin too (do not use 10w40 as it is know to cause sticky rings in those engines because of high VI content)

THere is nothing weak about the locking pawl in a 203. A ll of these where converted to part time with some after market kits but some of the kits were low quality and gave 203 a bad name. If you properly service/change lube in it, it is a tuff case. Also use striaght 30w non detergent oil in it, not muilt vis detergent oil as it foams a lot more and reduces lubrication and can shorten units life. (lot of people do this wrong) You can use striaght 20w non detergnet in winter if you want too.

I am not sure but it should be around 18 to 20 gauge.

----------------- The SnoMan

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SnoMan

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