1972 factory correct questions - The 1947 - Present Chevrolet & GMC Truck Message Board Network

1972 Jimmy · 01-11-2015, 04:50 PM

Hello All!
Need some help determining a couple of things to get my 350ci motor back factory correct for my 1972 Jimmy.

First, what are the correct valve covers. I have not found any good pics showing both right and left hand covers. How many holes are suppose to be in each cover and what are each of the holes for??

Second, what style of water pump came from the factory Short or Long?

Third, how is this motor timed? Straight vertical or from 2-3 O’clock position
Any Help would be appreciated!

Thanks,
Eric

asolde · 01-11-2015, 07:35 PM

The valve cover on the drivers side should have two holes one forward for the pvc valve and one aft for the oil fill tube. The valve cover on the passenger side should have one hole aft for the oil breather back into the carb.

Should be a short water pump.

Timing marks should be at the 2 o clock position

**IronCanine** · 01-11-2015, 07:54 PM

I think asolde is right for the majority of 350s, but I also don't think a two hole passenger side valve cover would be incorrect for a 72.

Check out this Survivor engine thread:

http://67-72chevytrucks.com/vboard/s...=549556&page=2

...I've also attached a couple of pics. One from that thread and one from DeadheadNM's build thread and his motor pulled from a low mileage 72 burb.

1972 Jimmy · 01-11-2015, 09:48 PM

Awesome guys!! Thank you for the help! Looks like its shopping time!

Eric

1972 Jimmy · 01-11-2015, 09:54 PM

By chance would either of you two know if AC trucks came with a clutch assemble fan? Are the fans different between clutch assemblies and direct mount?
Eric

drillrod · 01-11-2015, 11:00 PM

All three of my 72 trucks with 350 engines had two hole valve covers on each side! Mine are all original because they still had the engine emissions certification label with the manufacture date on the passenger side valve cover.

drillrod · 01-11-2015, 11:04 PM

My AC trucks came with clutch fans. I am not sure if it is the same fan as non AC trucks or not.

1972 Jimmy · 01-13-2015, 10:00 PM

by chance does anyone of you guys know what is the stock diameter of the harmonic balancer. Is it a 6" or a 8" standard for our trucks

**IronCanine** · 01-13-2015, 10:53 PM

I believe it's 6-3/4 inches. If you need one I think this should do it with the factory correct appearance:

http://www.dormanproducts.com/p-2011...cer&origin=YMM

...and most any big box parts place will have them.

If you've got one you want rebuilt, you might try this guy:

http://www.damperdoctor.com

01-11-2015, 04:50 PM	#1
1972 Jimmy Registered User Join Date: Nov 2012 Location: Freeland, Michigan Posts: 1,385	1972 factory correct questions Hello All! Need some help determining a couple of things to get my 350ci motor back factory correct for my 1972 Jimmy. First, what are the correct valve covers. I have not found any good pics showing both right and left hand covers. How many holes are suppose to be in each cover and what are each of the holes for?? Second, what style of water pump came from the factory Short or Long? Third, how is this motor timed? Straight vertical or from 2-3 O’clock position Any Help would be appreciated! Thanks, Eric

01-11-2015, 07:35 PM	#2
asolde Registered User Join Date: Apr 2012 Location: Henderson Nevada Posts: 804	Re: 1972 factory correct questions The valve cover on the drivers side should have two holes one forward for the pvc valve and one aft for the oil fill tube. The valve cover on the passenger side should have one hole aft for the oil breather back into the carb. Should be a short water pump. Timing marks should be at the 2 o clock position __________________ 1972 cheverolet K5 CST Blazer 350/auto/AC/PS/PB/Aux Batt From Medford, Oregon

01-11-2015, 07:54 PM	#3
IronCanine I'm trying.... Join Date: Oct 2013 Location: Athens, GA Posts: 2,615	Re: 1972 factory correct questions I think asolde is right for the majority of 350s, but I also don't think a two hole passenger side valve cover would be incorrect for a 72. Check out this Survivor engine thread: http://67-72chevytrucks.com/vboard/s...=549556&page=2 ...I've also attached a couple of pics. One from that thread and one from DeadheadNM's build thread and his motor pulled from a low mileage 72 burb. Attached Images __________________ 1970 K20 Z62 https://67-72chevytrucks.com/vboard/...56#post9334756 1970 Blazer http://67-72chevytrucks.com/vboard/s...d.php?t=645076 1969 K10 SWB CST http://67-72chevytrucks.com/vboard/s...52#post8520352 1971 K20 Z84 https://67-72chevytrucks.com/vboard/...90#post9047290 1946 B.F. Avery Model A Tractor http://67-72chevytrucks.com/vboard/s...55#post8292555 "Sometimes I wonder if zander208 was even real..."

01-11-2015, 09:48 PM	#4
1972 Jimmy Registered User Join Date: Nov 2012 Location: Freeland, Michigan Posts: 1,385	Re: 1972 factory correct questions Awesome guys!! Thank you for the help! Looks like its shopping time! Eric

01-11-2015, 09:54 PM	#5
1972 Jimmy Registered User Join Date: Nov 2012 Location: Freeland, Michigan Posts: 1,385	Re: 1972 factory correct questions By chance would either of you two know if AC trucks came with a clutch assemble fan? Are the fans different between clutch assemblies and direct mount? Eric

01-11-2015, 11:00 PM	#6
drillrod Registered User Join Date: May 2014 Location: Rose Hill NC Posts: 193	Re: 1972 factory correct questions All three of my 72 trucks with 350 engines had two hole valve covers on each side! Mine are all original because they still had the engine emissions certification label with the manufacture date on the passenger side valve cover.

01-11-2015, 11:04 PM	#7
drillrod Registered User Join Date: May 2014 Location: Rose Hill NC Posts: 193	Re: 1972 factory correct questions My AC trucks came with clutch fans. I am not sure if it is the same fan as non AC trucks or not.

01-13-2015, 10:00 PM	#8
1972 Jimmy Registered User Join Date: Nov 2012 Location: Freeland, Michigan Posts: 1,385	Re: 1972 factory correct questions by chance does anyone of you guys know what is the stock diameter of the harmonic balancer. Is it a 6" or a 8" standard for our trucks

01-13-2015, 10:53 PM	#9
IronCanine I'm trying.... Join Date: Oct 2013 Location: Athens, GA Posts: 2,615	Re: 1972 factory correct questions I believe it's 6-3/4 inches. If you need one I think this should do it with the factory correct appearance: http://www.dormanproducts.com/p-2011...cer&origin=YMM ...and most any big box parts place will have them. If you've got one you want rebuilt, you might try this guy: http://www.damperdoctor.com __________________ 1970 K20 Z62 https://67-72chevytrucks.com/vboard/...56#post9334756 1970 Blazer http://67-72chevytrucks.com/vboard/s...d.php?t=645076 1969 K10 SWB CST http://67-72chevytrucks.com/vboard/s...52#post8520352 1971 K20 Z84 https://67-72chevytrucks.com/vboard/...90#post9047290 1946 B.F. Avery Model A Tractor http://67-72chevytrucks.com/vboard/s...55#post8292555 "Sometimes I wonder if zander208 was even real..."



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