71 C10 is now out of storage: and the bad news is

[57T210]

Hey Folks.

Yesterday, retarded the timing to about 6 degrees advance from 16 or thereabouts. While the 350 has a mild cam in it, just ran too 'tight' for my taste. Also backed off on the idle set screw to bring the idle down to about 900 or thereabouts. Ran well in the shop when it was already warm.

Getting ready for Md inspection so the 1/2" holes the P.O. had drilled through the exhaust pipes (before the mufflers) had to be repaired. Sounded cool but Md Inspection would never have passed me. So closed those Babies up this morning.

Backfired through the carb (a Holley, probably 600 or 650) a couple of times when I tried to start it this morning but it finally started running smooth - in the shop. Took it out on the road and it ran like crap.

Probably need to advance the timing some more but I couldn't help but 'feel' that the increased back pressure through the exhaust had something to do with it. Mufflers are new but tiny little guys (maybe 18 or 20 inches) up over the axle.

You Folks have any thoughts on this?

Thanks.

[67ChevyRedneck]

My truck is running a stock cam and I have it at 12 degrees BTDC. Runs great.

I used to have it at 6 because that's what the haynes book said, but it ran like crap. Most fellas on here seem to have it between 8-12 for stock motors with HEI.

My idle is about 900 in P and 700 in D.

I can't see how a muffler would create that much back pressure unless it is plugged.

I'd bump the timing back.

What kind of carb are you running?

On an edelbrock you can turn the screws until it begins to die and turn back 1/4 turn and that should get you real close to what you want.

Good luck.

[71chevylowrider]

Definetly dial the timing in, but i read somewhere that if it backfires through the carb, it's running too lean, & if it backfires through the exhaust, too rich? Maybe one of our motor guys can elaborate/explain it better. Also if it's one of the Holly models that have a power valve, that might be blown out also.

[Ron 586]

If it's a Holley and it backfired through the carb it 9 times out of 10 has blown the power valve. And that will make it run like crap.

[1BadSS]

You don't need an inspection in MD on a vehicle that old. $101 in and out with tags same day. They don't sniff it or inspect it. Tag it antique.

[centsless]

Originally Posted by 1BadSS

You don't need an inspection in MD on a vehicle that old. $101 in and out with tags same day. They don't sniff it or inspect it. Tag it antique.

I agree. The way the restriction for antique tags is listed is that the vehicle isto be used on weekends, holidays,and for occasional use only. As long as you do not use it as a daily driver, you are fine. The renewal for mine came in today, it is $51 for two years.

[1BadSS]

Originally Posted by centsless

I agree. The way the restriction for antique tags is listed is that the vehicle isto be used on weekends, holidays,and for occasional use only. As long as you do not use it as a daily driver, you are fine. The renewal for mine came in today, it is $51 for two years.

I daily drove my 65 Antique Tagged in MD for nearly two years up until I moved to KS in July.

[BurnoutNova]

my nova and my truck have historical plates on them, $68 bucks one time, never buy new plates again. i drive them all the time and the cops ave never bothered me. hell, i have open headers in my nova it sounds like a sprint car going down the road and cops never mess with me... good 'ol nebraska

[57T210]

Thanks Folks. Thought about going the classic tag route (have them on my 54 Belair) but will use the truck too much for my insurance co's restrictions.

Advanced the timing and while it runs better, drinks gas like I drink other stuff. I think the old Holley has bit the dirt and we'll be swapping in an Edelbrock tomorrow.

A bucket of rust in a bad paint job...why are these things so much fun?

Regards.

[Boog]

Put in a fresh set of AC plugs while you're at it. It can only help.