1983 K20 - Pep her up or leave her alone??

Okay, so my '83 K20 is amazing. The wife and I love driving her. Heck, it was her late daddy's rig, and it's the truck she learned to drive a ton of years ago, so it makes sense. Plus, she looks amazing and drives just like you'd expect.

When I first learned I was going to be resurrecting her, I had all these grandiose ideas about pepping up the mighty mouse 350 with an intake, heads, RV cam, headers and such. Might as well throw in some chrome while I'm at it too! Totally my wife's decision, by the way. lol This would require cleaning up the engine bay, to include getting rid of the smog system, and all that so I can have a nice clean 350 that, while she won't win any races (not trying to actually), she'll have a bit more pep in her step. In fact, I have all of the parts in my garage, just waiting on me to start.

Here's the thing. She's completely stock. Other than components that were replaced during the years (alternator, starter, fuel pump, etc...), and the muffler I had to replace, she's just like she rolled off the floor.

Do I do this to an all original truck? I'm not really worried about resale, as she'll never leave our family. And I know I can get her making some decent, non smogged horsepower, but "Just because I can, doesn't mean I should" comes to mind.

What are y'alls thoughts? Would you leave her be, or give her a little shot in the pants...?

Thanks folks, and have a great weekend!

Edit - Added heads to the potential upgrade list

It's only my opinion, but things are only original once and there are fewer and fewer of those as each year passes. I would leave it alone and continue to enjoy it as is.

Trash the 350 and go Big Block!!! Put a smile on the little Lady's face, she'll love it once she puts her right foot down to the floor!!! Just sayin....

Midnightmoon said:

It's only my opinion, but things are only original once and there are fewer and fewer of those as each year passes. I would leave it alone and continue to enjoy it as is.

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I have to agree..

Paladin said:

Trash the 350 and go Big Block!!! Put a smile on the little Lady's face, she'll love it once she puts her right foot down to the floor!!! Just sayin....

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What he said!

Don’t get confused and think there is some magic “smog equipment” you can remove to make the engine run really better. Most of the smog equipment is the EGR and some vacuum or electrical devices that make it more of a PIA to troubleshoot, but most of it has very little performance impact. The real problem is the old design smog-era heads with very low compression, and tuning specs that are designed to lower emissions.

- You can leave everything in place and tune it a little better on your own . Advance base timing, recurve the mechanical advance, and rebuild the Quadrajet to make sure it’s working correctly. That might make enough difference to keep you happy.
- Next step would be a new intake, cam and headers, and most will work without taking off the emissions equipment. However, the lame cylinder heads and low compression will always limit the gains. In many respects you are putting very nice lipstick on a pig.
- Next step after that is to move to Vortec iron or aftermarket aluminum heads, and this will start to give you real performance potential. It’s not hard at all to get it up to 330-350 HP and still have the low end torque you want in a heavy truck. Just don’t go wild and pick a cam that is better suited to a light car with low gears and a 4 speed. You need torque in the right power band, not high RPM horsepower.

With an original truck I think I would just try tuning and tweaking it a little to see if I like it. It’s always great to find a truck like that, and I think it would make it much more unique.

'Preciate all the feedback. The wife and I are still on the fence about this. lol

That being said, if we WERE to perform the upgrades, as I pull pieces off of her, my plan was to clean them up, good as new, oil 'em down real nice, and seal them up. I could always go back to stock if I want to.

75gmck25 said:

Don’t get confused and think there is some magic “smog equipment” you can remove to make the engine run really better. Most of the smog equipment is the EGR and some vacuum or electrical devices that make it more of a PIA to troubleshoot, but most of it has very little performance impact. The real problem is the old design smog-era heads with very low compression, and tuning specs that are designed to lower emissions.

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Regarding the smog equipment, I'm actually not contemplating removing smog for performance reasons. As Derek would say, I would probably only gain about 0.69217 HP out removing all that. LOL What I WOULD gain, is a cleaner engine bay. Dreams of a nice, clean small block 350 sitting in there WITHOUT 4273 miles of vacuum lines, hoses, doo-dads, and what-nots fill my head. lol

Oh, and I should probably go up and edit my original post. If I go down this rabbit hole, aftermarket heads would definitely be included in the upgrade list.

For now, I'll keep running her like she is. And anyway, I've got a few issues I need to get taken care of before the top end of the 350 gets opened up (if ever):

• Get my factree gauges working (maybe install the RPM gauge where the fuel gauge is?)
• Replace headliner
• Repair/replace dash
• Replace cigarette lighter (no smoking, but I don't like things that don't work lol)
• Replace door hinges
• Fix the danged vent window seals
• Clean and undercoat the frame/under belly
• Detail the engine bay

Better get started...

Thanks again for y'alls thoughts!

Save the unicorns!

Although I have to admit, those tachometer conversion kits that LMC sells are a sweet upgrade and wouldn't harm the "stock" nature of the truck.

Other than that I'd leave it alone.

I like 350 engines.By putting some good performance heads,flattop pistons and a mild cam with a good intake/carb combo they really stand out.

So really, to wake that engine up, you don't need to go with a full build. Re-curve the distributor advance, richen up the fuel mixture in the carb and add the headers with a free flowing exhaust.

Of course the emissions will be high, but if that is not an issue, you're good.

My 1980 K10 is completely original other then normal replacement items and I won't change a thing, like the dude above said they're only original once.

They only made like um...ten million of them. If its not a numbers matching, showroom new vehicle, well then it's just another concoction of steel, glass and plastic wrapped around 4 wheels. You want a truck that you can drive like a modern day vehicle? Well then roll up yur sleeves, break out the saving account and let r rip tater chip.

My k20 was an original, and it was nice. The engine pucked, put in a circle track motor, sounded awesome, more power, but no vacuum. Saw a 454 for 1500.00 rebuilt snapped it up, ol' motorhome gen lV, pulled it apart tp double check, and all well within spec. RV cam RPM air gap, holly 750, so much better then the 350's. All that to say this, My truck is a daily driver, my heart beats a little faster each time in climb aboard, struggle not to do burnouts, hauls a trailer as much as solo, drive it hard and keep it up, and I am old tooo.... second pic is the rpm and A/F ratio gages as you were interested in a tach. You know you want that BBC.

@Craig Nedrow Good oil pressure, but the tach must not work, only 600 rpm?? Should be at least 5000 and climbing

Put me in the keep it stock category.

However, when the time comes to do a "heart transplant" - well, then that is the time to do some upgrades and make that a purty , powerplant plus minimal vacuum hoses kind of deal.


My plan on mine - mainly because I want to be cheap with the old ragged out engine for as long as possible. Spread my love ( $'s ) to the other vehicles as long as I can.


Man, did I pick an expensive hobby.