1968 Engine Identification

[Mosesatm]

I'm getting the engine ready to replace the valve seals. The engine is not original but it is stamped as a '68, so far so good.

The heads, on the other hand, are a different story. Both are stamped "302", one is dated 0J30 (September 30, 1970), and the other is dated 1K30 (October 30, 1971), both have a large "T" cast into them, under the valve covers. I have no idea what the "T" means, and haven't been able to find anything online. Do any of you know whether these are 2V or 4V heads?

Do heads have a casting number somewhere that is visible without removing them?

Another issue is that the rocker nuts are 9/16 instead of the normal 5/8, and they release immediately instead of having tension all the way. They seem to have been torqued to a hard stop. Any idea what's going on there? Does the car possibly have a roller cam?

Thanks for any help.

ETA
I learned that all 302 heads after '68 had non-adjustable screw-in rocker studs, so that solves one mystery. I'm going to assume these are standard 63cc heads.

 

[robert campbell]

Arlie,
The 290 HP 4V 302 engine was a one year offering in 1968. It came with the 4V heads as you know with 53 CC combustion chambers that raised the compression to around 10.5 to one. After that all 302 heads to my knowledge are 63 CC until the 90's. None are noted as "4V'. And as you already know you have the non-adjustable valve train. It is important to keep valve stem height correct and if the heads have been surfaced this can affect valve adjustment. They do make longer pushrods in .030 increments to compensate for valve tip and rocker arm tip wear. I never like them and replaced them with screw in studs to be able to adjust the valves properly.

Rob

 

[CougarCJ]

I'm getting the engine ready to replace the valve seals. The engine is not original but it is stamped as a '68, so far so good.

VIN stamped? and/or C8OE-6015-A?

What is the casting date?

 

[Mosesatm]

Arlie,
The 290 HP 4V 302 engine was a one year offering in 1968. It came with the 4V heads as you know with 53 CC combustion chambers that raised the compression to around 10.5 to one. After that all 302 heads to my knowledge are 63 CC until the 90's. None are noted as "4V'. And as you already know you have the non-adjustable valve train. It is important to keep valve stem height correct and if the heads have been surfaced this can affect valve adjustment. They do make longer pushrods in .030 increments to compensate for valve tip and rocker arm tip wear. I never like them and replaced them with screw in studs to be able to adjust the valves properly.

Rob

Non-adjustable rockers do seem a bit odd. I’m with you in that I like knowing they are all properly adjusted.

 

[robert campbell]

The 390/428 engines in the late 60's went to non-adjustable. The 302/351W and even the 351C engines also went that way. The Boss 351 and 302 retained adjustable rockers as they were solid lift cams.

I never liked non-adjustable rocker arms..... Pontiac and others went this way also...

Rob

 

[rvrtrash]

I think the manufacturers were trying to make the engines more "reliable". So many people don't know how to adjust rockers, or want to. They just want to get in and drive. I saw a 350 chevy with two rows of bent pushrods and a new cam with flattened lobs because the guy misunderstood what "resistance on the push rod" meant. He thought that meant you couldn't turn it at all. He brought it to me to fix because it didn't run so well.

Steve

 

[Mosesatm]

Two rocker nuts are stubborn and don’t want to release. Is it ok to remove the studs with the nuts?

 

[Mosesatm]

Two rocker nuts are stubborn and don’t want to release. Is it ok to remove the studs with the nuts?

 

[robert campbell]

So is the entire stud spinning? If so they are pressed in and you will need a stud puller to get them out. Then they need to be pressed back in. One of the problems with "press fit rocker studs" is that they like to pull out. That screws up your valve lash. That is why the Hipo 289 has screw in studs.

I nice upgrade to your heads would be screw in studs and adjustable rocker arms. Now you know me, I would not spend a penny on rebuilding stock heads. You can buy two Edelbrock E street aluminum heads for $1k. By the time you rebuild your heads you will more than likely have at least $500 bucks in them. The E street heads are FAR superior to stock heads. They come with screw in studs and guide plates. Add a mild cam and some shorty headers and bingo, 100 HP gain with the proper tuning.

Rob

 

[Mosesatm]

I think the manufacturers were trying to make the engines more "reliable". So many people don't know how to adjust rockers, or want to. They just want to get in and drive. I saw a 350 chevy with two rows of bent pushrods and a new cam with flattened lobs because the guy misunderstood what "resistance on the push rod" meant. He thought that meant you couldn't turn it at all. He brought it to me to fix because it didn't run so well.

Steve

Wow, I’m surprised it ran at all!! Was there any damage?
I always spin the push rods until they stop, then another 1/2 turn. Some say 1/2 and others say 3/4.

 

[robert campbell]

I do 1/2. Sometimes 1/4 turn. The trick is to ensure that the lifter is completely filled. On new motors I pump up the system and do 4 holes and then pump again for the final 4 holes.

The trick on new engines is to know the difference between the feel of a "dry" lifter. The spring in the lifter is not that strong and it is hard to discern by spinning the push rod. The difference between a tiny bit of "lash" and then contact is very slight. People will go all the way to full lock down. Trying to manually prelube the lifters is very difficult and not nearly as good as pumping up the engine with a drill motor. And even when readjusting an engine that has set around a long time it is best to spin up the oil pump with your trusty 1/2 drill motor.

I go through the complete firing order and then come back to number one on fully pumped up lifters. After doing all of them and coming back to number one you will notice that you can again spin the push rods on number one. That is due to forcing the oil out of the lifter as it goes through the valve opening cycle.

I seldom need to readjust the lifters using this method. Very easy on the engine stand vice in the car.

Rob

 

[rvrtrash]

Wow, I’m surprised it ran at all!! Was there any damage?
I always spin the push rods until they stop, then another 1/2 turn. Some say 1/2 and others say 3/4.

When I say he brought it to me, I should have said he came to me and asked me to fix it. It was transported to my house on my car trailer because he couldn't keep the motor running, decided he was going to fix it, started taking the engine apart and figured out he didn't know what he was doing. I was just trying to be brief before. I ran a compression check and he hadn't bent any valves, just ruined the cam, lifters and push rods. He told me that he kept tightening the rockers as the engine ran worse and worse, so the bending and wiping didn't happen all at once. He actually put effort into destroying the cam.

Steve

 

[robert campbell]

Ouch!!!!

 

[stangfan]

When I say he brought it to me, I should have said he came to me and asked me to fix it. It was transported to my house on my car trailer because he couldn't keep the motor running, decided he was going to fix it, started taking the engine apart and figured out he didn't know what he was doing. I was just trying to be brief before. I ran a compression check and he hadn't bent any valves, just ruined the cam, lifters and push rods. He told me that he kept tightening the rockers as the engine ran worse and worse, so the bending and wiping didn't happen all at once. He actually put effort into destroying the cam.

Steve

That is an expensive lesson...

 

[Ruppstang]

Some people just have to learn the hard way. I think it is good doing all that you can your self but you need to know your limits. When I have a carburetor problem I call Rob.

 

[robert campbell]

Thanks Marty! Dinosaurs who know carbs a bit are quickly going towards extinction!! A lot of EFI out there for old engines, but it is still hard to beat a well adjusted carb for price and reliability.

I know my limits in lots of areas both construction and cars!! I get "handy with money" in those cases!! I learned to not try to replace a shower faucet on the weekend with no ability to close a valve to just the shower...….. I think it was a $900.00 dollar lesson on a Saturday. Wife was very happy with me...… Not.....

 

[Mosesatm]

Here’s another identification question. This is supposed to be a Ford 9” rear. It’s limited slip and as you can see it has 3.23 written on it.
Does this look like a typical 9”? Is there a date code on it?

Thanks

 

[Ruppstang]

IMHO that is not a 9 inch rear axel.

 

[CougarCJ]

Maybe a 9-3/8?

 

[robert campbell]

IMO definitely a 9 inch rear end. They are more round than the 8 inch on the bolting surface. Very common in "GT" equipped cars in 1968 with the J code or larger engine with a 4 speed. Again, with the GT option.

Casting numbers may be on the flange surface and typically on the right side and on the inside the part number is cast into the main caps. Not sure if your car has the GT option or what tranny it has.

Rob