# Engine questions for pontiac 350 and cooling question



## virginiavenom (Feb 20, 2011)

ok. first question I have is I'm looking at pics of my engine I took as I'm on a training detail right now. and I notice my driverside head has a few stamps on it. please note that I don't know what means what, and what's good or bad, or to-do's for specific parts of a pontiac 350. the head has 2 numbers on it. one is J139. it has a GM at the front of the driver side head.

then the block has a faint number on it. under the number is a Y. the number reads the best I can tell G240097

also, I'm unfamiliar with the firing order and the cylinder numbering of this engine as well. can someone bring me up to speed on that? or point me in the right direction? I know this is not the factory motor for this car. however, I would like to know what year the motor came from if possible. right now it has a 650 CFM Weber carb, which I'm told is a good carb. it is a 4 barrel with an electric choke. I'm debating going to a holley or edelbrock or other carb though. carb looks to be in good condition. 

my next question is how do I tell what rear end gears my 10 bolt diff has? the diff cover has been replaced with a chrome one (no, I didn't do it)
what came standard with this car? what years and models is it interchangeable with? 

the last question I have is what radiator do I need to be looking for? seems like every place I look at has radiators for the car, but it is not the factory configuration with a T-350 and a 350 V8 for a pontiac tempest lemans. it's a 67 for those wondering. I'm hoping I can restore the radiator support as it is pretty decently rusted right now.

thanks for your help guys.

Phillip


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## virginiavenom (Feb 20, 2011)

it also appears to have a 1 and 1 seperated on the dual exhaust port on the head. don't know if that helps.


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## 68greengoat (Sep 15, 2005)

virginiavenom said:


> it also appears to have a 1 and 1 seperated on the dual exhaust port on the head. don't know if that helps.


The 11 is the head casting number.
11
1970 Production year
350ci
255hp
2.11/1.77 valves

The J139 that you mentioned in your 1st post is the head date code.
Nov. 13 1969

The "Y" should have another letter to the right. Y? I'm thinking it should be a U. Check the block casting number. It may be 9799916. That is, if those heads are original to your block. You can also date code the block by the distributor. Not sure if these numbers show up in your pix.


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## virginiavenom (Feb 20, 2011)

thank you sir. good to know. I'll see what I can find on the block


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## virginiavenom (Feb 20, 2011)

can anyone get back to me on the other questions? I was unable to see the block numbers.


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## jetstang (Nov 5, 2008)

350/255 HP doesn't have 2.11 valves, I know, I have the same deal.
1970 11 350 cu.in. D-PORT 1.96 1.66 73 CC 
Rear end codes are not on the cover, they are on the axle tube.
OK, it's a 67, for what I know there are 2 dif sizes based on with/without AC, one is taller than the other.
Firing order is typical GM 18436572.


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## Instg8ter (Sep 28, 2010)

just remember the firing order is counterclockwise....not clockwise like a chevy. Order radiator for 66-67' GTO, if the radiator support is a "U" channel on the bottom rung it is a standard non AC, if the bottom channel is an upside down "U" it is the heavy duty AC radiator. i picked up a three row alum. from Champion for around 200.00 application specific. and it fits in the standard support.


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## Thumpin455 (Feb 17, 2010)

1-8-4-3-6-5-7-2 firing order.

Number one is drivers side front cylinder, number two is passenger side front cylinder. Odd on drivers side 1-3-5-7 and even on passenger side 2-4-6-8.


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## virginiavenom (Feb 20, 2011)

anyone know what oil filter to use on this particular 350? I'm guessing it is a 70 or close to year. also, what radiator hoses should I get, or should I just go with universal?

thanks guys. getting closer and closer.


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## virginiavenom (Feb 20, 2011)

Instg8ter said:


> just remember the firing order is counterclockwise....not clockwise like a chevy. Order radiator for 66-67' GTO, if the radiator support is a "U" channel on the bottom rung it is a standard non AC, if the bottom channel is an upside down "U" it is the heavy duty AC radiator. i picked up a three row alum. from Champion for around 200.00 application specific. and it fits in the standard support.


hey man, I am looking for the one you got, and I can't seem to find it. the frame support is an upside down U with the U's to mount into of course. please shoot me a link if you can. Thanks man.

gotta adjust my rockers and get my starter wired up and coolant and oil in it and we can start turning it over to set timing. oh and put the headers on of course. :cool


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## Instg8ter (Sep 28, 2010)

here you go VirginiaVenom, you will need the HD radiator bumpers also you will want to buy a fan shroud from Ames and use the 17 1/2" clutch fan i have a 19" from 71' and had to trim the ends off to clear the shroud but once i got it fit it keeps the 463 at 165 cruising and not above 190 at idle.

3 Row Radiator 1966-1967 Pontiac Tempest Gto Lemans | eBay


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## virginiavenom (Feb 20, 2011)

Ordered. That is a pretty radiator. Should work nicely.


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## Instg8ter (Sep 28, 2010)

yes its a good bang for the buck as some others go for 4-500. and works perfectly so far....i drilled a small 3/32 hole in the thermostat ring to keep from getting air bubble in the system at initial start up before your thermostat opens, on pontiacs the key to cooling is the fan shroud and fan fit (1/2 blade in the shroud half out) before i fit the shroud it was running 200+ at extended idle shroud cut that down to 180 and at cruise sticks at 165 with 160 thermostat. and its a 463 so that should keep your 350 nice and cool.


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