GA Head Question

[sethj78]

Ok in reading that Ka thread i came across some one saying Ga seats are induction hardened. I googled the #'s on this motor and found that it was from a 1970 98. the block has the F cast on it but I talked to the head guy that everyone on here recomends and he said the Ga didn't come out till like 72 or 4 Whats the real deal here? And my big question's, r the seats hardened, if they r hard seats can I put 2.07 intake valves in them with out putting in new seats?

[svnt442]

What # did you google? There is no way to tell what the engine came out of from any of the numbers on the engine. All you can tell is what it is, where it was made, and what year it is.
The numbers CAST into the shelf just above the water pump next to the oil fill tube ID the engine it self (i.e. 350, 400, 455...). The numbers and letters PUNCHED into the machined pad on the left side of the engine under #1 spark plug will tell you what year it is and the plant where it was installed into the car it came in.
IF the pad is blank it is either before 1968 (not a 455 then) or a warranty block that the mechanic didn't finish his job by punching the numbers back onto the block.

Get those two numbers and we can tell you exactly what you have.

Also GA heads are from 1972. The block still could be from 1970 but you have to check the machined pad to find out.

[joe_padavano]

Originally Posted by sethj78

Ok in reading that Ka thread i came across some one saying Ga seats are induction hardened. I googled the #'s on this motor and found that it was from a 1970 98. the block has the F cast on it but I talked to the head guy that everyone on here recomends and he said the Ga didn't come out till like 72 or 4 Whats the real deal here? And my big question's, r the seats hardened, if they r hard seats can I put 2.07 intake valves in them with out putting in new seats?

As noted, the GA heads were only used in the 1972 model year. The seats are induction hardened, they are not pressed-in seats.

[Eightupman]

Even though this is NOT a proven fact, it seems to me just based on MY personal obervations that the smaller "A" is indicative of the hardened valve seats. I have seen ONE set of Ca heads and they were off a California Smog car with a smog pump and all. Then there is the #7 and 7a heads for 71/72 just at the unleaded transition year. But that is debunked by the 8 head in 1973 because they are all hardened after that, but no "a" indication. I'm not sure if there is a G and a Ga head though.

John

[J-(Chicago)]

There is a G and Ga head.

have 1 G head and one Ga head on my motor.

It didn't come stock like that of course, but I picked the 2 heads that had the best valve guides.

[sethj78]

Well I guess it doesn't matter what it came out of I just needed to know about the hard seats, and thanks for clearing that up. Ok now do u think it will b worth up grading to 2.07 intake valves, I would think if u put the big valves u have to put new seats too. These heads seem to b in pretty good shape and I may have the stuff to do the seats but not put new seats in so if its not worth the expense it will save me some money.

[sethj78]

I seen on ebay there is a listing for a C and a B paired together whats up with that ... just curious??

[Warhead]

Originally Posted by sethj78

Ok in reading that Ka thread i came across some one saying Ga seats are induction hardened. I googled the #'s on this motor and found that it was from a 1970 98. the block has the F cast on it but I talked to the head guy that everyone on here recomends and he said the Ga didn't come out till like 72 or 4 Whats the real deal here? And my big question's, r the seats hardened, if they r hard seats can I put 2.07 intake valves in them with out putting in new seats?

Since this was missed by everyone...
Only the exhaust seats get hardened, the intakes run cooler, and do not have the issue of burning down the seat (and lowering into the port) like the exhaust seats do. GET YOUR 2.072 valves, put them into whatever heads you get.
Big valves means a shop will have to grind, or cut the heads larger to fit the valve. This is what increases airflow, and horsepower.
I know you text guys like to shorten things up, r matey?
Jim

[sethj78]

I have seat cutters so I can do the intake and I have 1.68 or whatever exhaust and was gonna leave it the same. So this maybe good news for my budget!! So u r saying I won't have any problems at all with not having hard intake seats? I just want to make sure I'm understanding u correct...I can b a little slow in the head sometimes.

[Warhead]

Originally Posted by sethj78

I have seat cutters so I can do the intake and I have 1.68 or whatever exhaust and was gonna leave it the same. So this maybe good news for my budget!! So u r saying I won't have any problems at all with not having hard intake seats? I just want to make sure I'm understanding u correct...I can b a little slow in the head sometimes.

I would recommend that someone experienced in this do the operation, whether you have the cutters or not (to do a quality job you will need multiple angles). Cutting the 45 (or 30) seat wide for the larger valve will do nothing in terms of gaining airflow.
***If you have not done this job before, now is not the time to try it.***
Practice on a scrap head, with a qualified tech, or mentor who has done it before and is willing to take the time to show you how to properly do this procedure.
You get what you pay for, talk to Jim at J&S machine (Topeka, IL) - go to his website...
http://www.jsmachineoldsmobile.com/
The ONLY time I ever had to put in intake seats is when I had found porosity holes in 383-440 seats. A common 60's iron Chrysler problem.
That's my experience.
Jim

[Eightupman]

Originally Posted by Warhead

You get what you pay for, talk to Jim at J&S machine (Topeka, IL) - go to his website...
http://www.jsmachineoldsmobile.com/

I second Jim. Talked to him on the phone on several occasions. Is very knowledgeable. I purchased a set of heads from him and for the money I paid, I saved a few hundred vs a couple shops in my town. Plus these guys here didn't have a lot of Olds knowledge.

John

[sethj78]

Screw it I'm either putting all hard seats in and doin it right or I'm buying a set of aluminum heads. $1700 from summit assembled.

[Eightupman]

Originally Posted by sethj78

Screw it I'm either putting all hard seats in and doin it right or I'm buying a set of aluminum heads. $1700 from summit assembled.

I implore you to talk to either Jim and J&S or Rocket Racing. Those guys will build you better heads for that $1700 (or less) than the Ebrocks out of the box. Even though the are the most affordable aluminum head on the market, Ebrocks out of the box will not outperform the ones those guys build.

John

[joe_padavano]

Originally Posted by Eightupman

Even though this is NOT a proven fact, it seems to me just based on MY personal obervations that the smaller "A" is indicative of the hardened valve seats. I have seen ONE set of Ca heads and they were off a California Smog car with a smog pump and all. Then there is the #7 and 7a heads for 71/72 just at the unleaded transition year. But that is debunked by the 8 head in 1973 because they are all hardened after that, but no "a" indication. I'm not sure if there is a G and a Ga head though.

John

Sorry John, but I must again disagree with this line of reasoning. C heads were cast in the 1967-1969 model years, but the federal requirement for low-lead gasoline did not come into effect until the 1971 model year. There would have been no reason to build C or CA heads with hardened seats. Similarly, since it WAS a federal requirement to run on low-lead starting with the 1971 models, even the G and H heads came with hardened seats. Also, what about no. 8 heads? Since there was never an 8A, your logic would indicate that all no. 8 heads do NOT have hardened seats. That is not correct.

Olds used the "A" to indicate a minor casting change. That's why we have F and FA blocks, for example.

[sethj78]

I read that the F block was pre 71 and Fa was post 71? (I'm not disputing the casting change) Thats 1 reason I say my 455 is from a 70 98 the other is the carb #'s. Someone must have put 72 Ga heads on this 70 F block somewhere along the line and a reason for my confusion!! This thing was ran on leaded gas cuz it had this thick light gray paste around the end head bolts and other places. I was told that was from leaded gas.

[sethj78]

If I bought the Ebrocks, I found bare castings for $1300, I would work them over. I am by no means as good as those pros but I'm fairly handy. And have been dealing with this machineshop for years so I have learned so porting tricks. Besides I'm still thinking on the ebrock heads. I did talk to j&s he said he could fix me up but if I had a good machineshop close by I should use them.

[Eightupman]

Originally Posted by joe_padavano

Sorry John, but I must again disagree with this line of reasoning. C heads were cast in the 1967-1969 model years, but the federal requirement for low-lead gasoline did not come into effect until the 1971 model year. There would have been no reason to build C or CA heads with hardened seats. Similarly, since it WAS a federal requirement to run on low-lead starting with the 1971 models, even the G and H heads came with hardened seats. Also, what about no. 8 heads? Since there was never an 8A, your logic would indicate that all no. 8 heads do NOT have hardened seats. That is not correct.

Olds used the "A" to indicate a minor casting change. That's why we have F and FA blocks, for example.

Reread what I typed Joe. I stated that all #8 heads have hardened seats, therefore debunking my own logic.

John

[joe_padavano]

Originally Posted by Eightupman

Reread what I typed Joe. I stated that all #8 heads have hardened seats, therefore debunking my own logic.

John

Ah, sorry, I missed that.

[Texas Jim]

Since I moved away from here f/ 6 years, 2002 to 2008, I'm not up on who's doing any good machine work in this area. The old guy who was "the best," Mr. Bill Carter, who had done fantastic machine work since the 40s in this area, died when I first moved to Puerto Rico, in late 2002. He was the only person I trusted to do "exact" machining on anything I ever bolted together.
My question is; How expensive is the shipping from J&S? If it's not too much "over the top," I think it would be worth the money to get good work done. I KNOW that it's always well worth getting my machining done right the first time and not going w/ the cheapest prices. (That's the only way to go in any field.) Have any of you guys shipped anything to or from J&S to or from other states? Thanks in advance.

[J-(Chicago)]

Originally Posted by Texas Jim

Have any of you guys shipped anything to or from J&S to or from other states? Thanks in advance.

He's only about an hour and a half from here, so I wouldn't have to ship anything.

Eightupman has done shipping with them I believe. If he doesn't find this post soon you could PM him.

I have an intake J&S ported, but never bolted it on because of hood clearance issues. I have to find another hood to cut up to use it.

He seems to be a decent fellow, & helped sponsor the big Olds race at Byron Dragway this year.