Newbie Here....66 C20 A Few Questions

[NWSooner]

Greetings friends!

I'm a TRi-5 Chevy guy by nature but have always loved the 60's Chevy Trucks and when I found this one ROTTING away in the Pacific Northwest I had to rescue it!

1. The guy I bought it from told me it had the 250 in it, but I'm not confident he has much of a clue....How can I be positive which Inline 6 I have?

2. I've changed points, plugs, cap, wires, coil, adjusted valves and carburetor. It sounds OK but takes like a minute or longer for all of the fuel to burn up and idle down. Looks like the stock Rochester 1 barrel, would a rebuild kit be worth it or should I opt for a new carb all together or could it be another problem?

3. Needs a new muffler, any suggestions on what might add a nice little rumble to this old girl? Look I know it's a 6 banger but still I honestly think it had the original muffler on it, truck only has 54,000 original miles on it.

Thank you in advance!

NWSooner

[Praxiss454]

Need some pics, man!

On 1) You can look for a stamp on the engine block and use various websites to try to decode it. Also I believe if your piston heads are flat, its a 230, and if they're concave, it's a 250. Someone here who knows more than me can confirm this.

3) I don't know but my original muffler is falling apart so I am interested to see what others recommend.

[TJ's Chevy]

Originally Posted by NWSooner

Greetings friends!

I'm a TRi-5 Chevy guy by nature but have always loved the 60's Chevy Trucks and when I found this one ROTTING away in the Pacific Northwest I had to rescue it!

1. The guy I bought it from told me it had the 250 in it, but I'm not confident he has much of a clue....How can I be positive which Inline 6 I have?

2. I've changed points, plugs, cap, wires, coil, adjusted valves and carburetor. It sounds OK but takes like a minute or longer for all of the fuel to burn up and idle down. Looks like the stock Rochester 1 barrel, would a rebuild kit be worth it or should I opt for a new carb all together or could it be another problem?

3. Needs a new muffler, any suggestions on what might add a nice little rumble to this old girl? Look I know it's a 6 banger but still I honestly think it had the original muffler on it, truck only has 54,000 original miles on it.

Thank you in advance!

NWSooner

Howdy and welcome aboard!

To answer your first question, since that truck is a 66 and it's a C20 I would not be surprised if that I6 is a 292.
Fastest way to tell a 250 from a 292 is fuel pump location.
250's fuel pump is right behind the distributor and the 292's fuel pump is in the middle of the block just behind the engine mount.
If that was a 230 you could pull a spark plug and you'd find flat top pistons.

You Can rebuild the stock carb, but as old as it is I would suggest upgrading to a holley 2 barrel or a weber 32/36. Both would require adapters.

Flow master mufflers sound great on these engines as well as Dynomax and Magnaflow mufflers.

[NWSooner]

Praxiss I'll post some pics soon as long as an old man can figure out how to do so!

TJ, thank you so much for the helpful info, its definitely the 250 that lazy ass who owned it before was right! I think I'll try rebuilding the carb, why not save a few bucks and learn something along the way. Do you think that will some the problem of the fuel taking so long to burn off and idle down?

Cheers,

NWSooner

[DPowers]

This is what I put on my '66
http://www.brockmancustomparts.com/

[vince1]

I was surprised in finding a kit off the shelf at NAPA for very few dollars. It is an easy rebuild.

Make sure the gas cap is not pressurizing, as many of the caps that are being sold are without two way venting. It took me a while to figure out why my crankcase was filling full of gas.

My truck ran way better with HEI but that just tells me there was something wrong with the original distributor. Understandable considering it had been sitting for about twenty years.

[NWSooner]

DPowers, nice looking exhaust! This is a little more conservative build budget wise, thanks for sharing nonetheless.

Vince, I think you are definitely onto something regarding the gas cap not being vented correctly, I'll be getting a new cap this week, thanks much and also for the NAPA tip on the carb rebuild kit I will call them tomorrow.

Amyone smoking opr grilling meat tomorrow? Dumb question right! Ribs and chicken thighs for me!

Cheers,

NWSooner

[TJ's Chevy]

Originally Posted by NWSooner

Praxiss I'll post some pics soon as long as an old man can figure out how to do so!

TJ, thank you so much for the helpful info, its definitely the 250 that lazy ass who owned it before was right! I think I'll try rebuilding the carb, why not save a few bucks and learn something along the way. Do you think that will some the problem of the fuel taking so long to burn off and idle down?

Cheers,

NWSooner

If you rev it and it slowly comes down to idle that's a sure sign of a vacuum leak. It's common for air to leak around the throttle shaft. I'd spray some carb cleaner around that and the base gasket to check for leaks.