1968 327/350hp, a/c and HT Engine Stamp

[Bryan M.]

I'm going to start a new thread about my 1968 convertible, 327/350hp, a/c, 4-speed, ps, pb and a/c to get opinions about if the a/c belongs with my car. Please forgive me if it's too long.

The HT vs HP engine stamp has always bothered me due to not having a clear explanation about which stamp is correct or if both stamps are correct. Or maybe the 68 model year is so screwed up nobody knows for sure.

The car was a project I picked up about 12 years ago from a guy who had it tore apart in his garage for over 15 years. It had most, but not all of the parts with it. It had the engine, drive train, all the a/c evaporator housing parts still attached to the firewall. It's a long way from being an NCRS type of car but I tried put it all back together as close to the correct 68 configuration as I could in my garage. It turned out to be a nice Sunday driver.

The car has all the hard to duplicate factory a/c body modifications such as the passenger side upper cowl vacuum operated vent flap. The driverside lower floor vent is blocked off. It looks like it came that way from the factory.
I've included some pics of the usual id #'s such as, the engine stamp pad, block Id, block build date and the trim tag (please excuse the bent tag. I pulled at the corners to verify that the paint underneath was silver. It is.)
What else can I do to answer/verify that a/c belongs on this car?
Thanks to anybody whole tackles this exhausting 68 question.

[Bryan M.]

Re: 1968 327/350hp, a/c and HT Engine Stamp

Ummm.. I think I might have found a pretty good explanation in the archives.
I interpret this as meaning the HT stamped cars could indeed be equipped with a/c.
https://www.forums.ncrs.org/showthread.php?t=1223

[Larry M.]

Re: 1968 327/350hp, a/c and HT Engine Stamp

Ummm.. I think I might have found a pretty good explanation in the archives.
I interpret this as meaning the HT stamped cars could indeed be equipped with a/c.
https://www.forums.ncrs.org/showthread.php?t=1223

Bryan:

I know of a number of 1967 327/350 HP cars that have factory installed air conditioning and an engine suffix of HT. It simply means that they did not ALSO have factory power steering. My 1967 is like this....factory air conditioning but no factory power steering (or power brakes for that matter).

I would assume that the same holds true for 1968 with the 327/350 HP engine.

In your case, the power steering was probably added later in its life.

Larry

[John H.]

Re: 1968 327/350hp, a/c and HT Engine Stamp

I've always wondered why Engineering assigned a unique suffix to an as-shipped small-block with A/C and P/S. In '67 they did for an L-79, but not for a 300hp; what was different in terms of the L-79 engine build at Flint V-8 in 1967 because of A/C and P/S? Anyone know?

[Bill C.]

Re: 1968 327/350hp, a/c and HT Engine Stamp

Hi,
As I understand it, the key is in the water pump and crankshaft pulley combination's required for an air car vs a 350 w/o air car.Non air uses shallower thinner pulley grooves, this was the case on all low horse sb's with A/C. an add on 3rd crank pulley was used with a flat stamped pulley on the p/s pump. This also left one empty set of grooves for the a/c belt if needed.

When 350 hp was specified that called for water pump and crank pulleys of deep groove style, ( with or without p/s ) with the use of an offset cast iron p/s pump pulley that used a belt running off the empty groove ( the other driving the alt)

Where does that leave the a/c belt? No place to run, so in that case I think they were forced to use the lower horse pulleys and arrangement on the 350 hp and a/c car in order to be able to run all the belts.

Maybe that created the different engine code?

[Terry M.]

Re: 1968 327/350hp, a/c and HT Engine Stamp

I think the pulleys went on at St Louis, so they are not included in the engine plant permutations.

How about the oil pan for PS and non-PS? PS will not fit with a 6-quart pan. I am just throwing that out as a guess.

[Bill C.]

Re: 1968 327/350hp, a/c and HT Engine Stamp

Terry,
I thought the 350 hp engines all came with the 5 qt pan so all would clear P/S, thought that started in 65, if thats the case, it would have no influence on a/c.
This one interesting!
Bill

[Jim T.]

Re: 1968 327/350hp, a/c and HT Engine Stamp

Bryan your description of the factory air conditioning installed pieces on your 68 and having the drivers side vent blocked off pretty much confirms in my opinion that your 68 came from the factory with air.
Having a 68 convertible with your options is really nice to have. You have a powerful, great performance all weather enjoyment Corvette to enjoy.

30 years ago I bought a book on option changes an owner could make to a C3. Reason I got it was for the article (how to ) on installing AC on a C3 that did not come from the factory with AC. Still have my original 68 and have yet tackled installing factory air. It involved a lot more work than I wanted to tackle although it can be done.

My 68 327/350HP has a 5 quart oil change. Is also equipped with the steering dampner (shock absorber) under the front of the oil pan.

[Terry M.]

Re: 1968 327/350hp, a/c and HT Engine Stamp

It IS interesting.
Just as an asside it took us a long time to figure out why there are two codes for 1970 LT1 (CTU & CTK). This one sounds like it will be longer. It might just take two real original cars sitting side by side to figure it out. That is what it took for the 1970.

[Bryan M.]

Re: 1968 327/350hp, a/c and HT Engine Stamp

Bryan:

I know of a number of 1967 327/350 HP cars that have factory installed air conditioning and an engine suffix of HT. It simply means that they did not ALSO have factory power steering. My 1967 is like this....factory air conditioning but no factory power steering (or power brakes for that matter).

I would assume that the same holds true for 1968 with the 327/350 HP engine.

In your case, the power steering was probably added later in its life.

Larry

Larry,
If it was an addition, whoever did it, did a jam up job. It has every factory part in the AIM. Even the engine is tapped for the lower ps bracket.

Bryan your description of the factory air conditioning installed pieces on your 68 and having the drivers side vent blocked off pretty much confirms in my opinion that your 68 came from the factory with air.
Having a 68 convertible with your options is really nice to have. You have a powerful, great performance all weather enjoyment Corvette to enjoy.

30 years ago I bought a book on option changes an owner could make to a C3. Reason I got it was for the article (how to ) on installing AC on a C3 that did not come from the factory with AC. Still have my original 68 and have yet tackled installing factory air. It involved a lot more work than I wanted to tackle although it can be done.

My 68 327/350HP has a 5 quart oil change. Is also equipped with the steering dampner (shock absorber) under the front of the oil pan.

Jim, That's one of the reasons I picked this project up. It's nice to have a little a/c in FLA.
My car also has the 5-quart pan

It IS interesting.
Just as an asside it took us a long time to figure out why there are two codes for 1970 LT1 (CTU & CTK). This one sounds like it will be longer. It might just take two real original cars sitting side by side to figure it out. That is what it took for the 1970.

Terry, If you find those two original unmolested 68s, please take a pic of the a/c idle solenoid set-up. I've been looking for a pic of that set-up for 12 years. I think over the years, that I have looked at every 68 sb a/c car for-sale over the internet and yet to see one with the set-up on it.

[John H.]

Re: 1968 327/350hp, a/c and HT Engine Stamp

Larry,
If it was an addition, whoever did it, did a jam up job. It has every factory part in the AIM. Even the engine is tapped for the lower ps bracket.

Bryan -

Every small-block ever made has those holes drilled and tapped from the engine plant; they weren't unique to any particular end application.