250 CID head - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Zogbert · 11-17-2016, 11:52 AM

I've got a 1972 C-10 with a L-6 250, casting 3994257. I looked at the plugs, and they aren't tapered, which the stock engine should have had (R-46T). Upon inspection of the plug hole, the hole has no taper. The head is a greenish color, while the rest of the motor is orange. It's obviously been changed.

The plugs in there are AC Delco R44XLS, which is the correct plug for a 1966 to 1969 250 CID and older 230 CID engines.

Any way for me to tell what year and engine the head is from? I don't see any casting number.

GRX · 11-17-2016, 04:24 PM

As you have probably surmised by now, you have a pre-1973 head which takes the older style gasketed spark plugs. Look for the casting number and casting date under the valve cover by the gasket rail on port side.

**'68OrangeSunshine** · 11-17-2016, 05:35 PM

Green factory paint indicates a '63-'66 MY 292. Only 292s were Alpine Green. 230s and 250s were blue, IIRC.
In '67 Chevy went to Chevy Engine Orange on all engines, L6s, and V8s, both SBC and BBC.
292 head on a 250 is OK.

Zogbert · 11-17-2016, 07:01 PM

There's not much paint left, but I would say it is green. The listed plug for that head is an AC Delco R44XL or an R45XL. If it's a 230 or 25 head, it's listed as an R44LXS or an R45XLS.

Much difference between those?

I'll pull the valve cover to see the casting number.

Thank you, gentlemen.

**'68OrangeSunshine** · 11-18-2016, 01:31 AM

The R45XLS is one stage hotter than the R44XLS. I used the 44s in my 292.
When AC Delco plugs started being made in Mexico, I switched to Denso 5029.

Zogbert · 11-18-2016, 09:14 AM

Thanks. I'll try to find those.

**'68OrangeSunshine** · 11-18-2016, 08:50 PM

Quote:

Originally Posted by Zogbert

Thanks. I'll try to find those.

Sorry I gave you the wrong part number, before I checked mine.
The 5029s are too small for an early head and have a 5/8'' hex. The right plugs are 3057 with a 13/16'' hex head.
The parts guys screwed me up and I had to trade 'em out yesterday.

Zogbert · 11-19-2016, 10:07 AM

I noticed those were tapered. I'll live in the middle of nowhere, so there are no auto parts places nearby. I hadn't headed over right away. I'll get some Monday.

Thanks!

11-17-2016, 11:52 AM	#1
Zogbert Registered User Join Date: Feb 2008 Location: Falcon Beach, Manitoba Posts: 37	250 CID head I've got a 1972 C-10 with a L-6 250, casting 3994257. I looked at the plugs, and they aren't tapered, which the stock engine should have had (R-46T). Upon inspection of the plug hole, the hole has no taper. The head is a greenish color, while the rest of the motor is orange. It's obviously been changed. The plugs in there are AC Delco R44XLS, which is the correct plug for a 1966 to 1969 250 CID and older 230 CID engines. Any way for me to tell what year and engine the head is from? I don't see any casting number.

11-17-2016, 04:24 PM	#2
GRX Registered User Join Date: Jul 2010 Location: MD Posts: 1,937	Re: 250 CID head As you have probably surmised by now, you have a pre-1973 head which takes the older style gasketed spark plugs. Look for the casting number and casting date under the valve cover by the gasket rail on port side. __________________ 1969 c-10 Step Side Long Bed. I-6 250cid = = 1969 Pontiac GTO hard top. 400, 4-speed.

11-17-2016, 05:35 PM	#3
'68OrangeSunshine Senior Member Join Date: Feb 2002 Location: Tucson, AZ USA Posts: 7,423	Re: 250 CID head Green factory paint indicates a '63-'66 MY 292. Only 292s were Alpine Green. 230s and 250s were blue, IIRC. In '67 Chevy went to Chevy Engine Orange on all engines, L6s, and V8s, both SBC and BBC. 292 head on a 250 is OK. __________________ Every 25 years I like to rebuild that 292, whether it needs it or not.

11-17-2016, 07:01 PM	#4
Zogbert Registered User Join Date: Feb 2008 Location: Falcon Beach, Manitoba Posts: 37	Re: 250 CID head There's not much paint left, but I would say it is green. The listed plug for that head is an AC Delco R44XL or an R45XL. If it's a 230 or 25 head, it's listed as an R44LXS or an R45XLS. Much difference between those? I'll pull the valve cover to see the casting number. Thank you, gentlemen.

11-18-2016, 01:31 AM	#5
'68OrangeSunshine Senior Member Join Date: Feb 2002 Location: Tucson, AZ USA Posts: 7,423	Re: 250 CID head The R45XLS is one stage hotter than the R44XLS. I used the 44s in my 292. When AC Delco plugs started being made in Mexico, I switched to Denso 5029. __________________ Every 25 years I like to rebuild that 292, whether it needs it or not. Last edited by '68OrangeSunshine; 11-18-2016 at 01:37 AM.

11-18-2016, 09:14 AM	#6
Zogbert Registered User Join Date: Feb 2008 Location: Falcon Beach, Manitoba Posts: 37	Re: 250 CID head Thanks. I'll try to find those.

11-19-2016, 10:07 AM	#8
Zogbert Registered User Join Date: Feb 2008 Location: Falcon Beach, Manitoba Posts: 37	Re: 250 CID head I noticed those were tapered. I'll live in the middle of nowhere, so there are no auto parts places nearby. I hadn't headed over right away. I'll get some Monday. Thanks!



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