1972 Lt1 w/press-in studs and 2.02/1.94 valves

[Jerome P.]

I know you're going to say this can't be, but here goes:

My 1972 LT1 w/ac has press-in rocker studs and 2.02"/1.60" intake/exhaust valves. With the exception of a few individuals they all say 70-72 LT1 came with screw-in rocker studs, guide plates and 2.02"/1.60" valves. Other say this was the case with late 1972 model year LT1's.

All the pertinent casting #'s and date codes are right on and within the date code tolerances. See the following:


Vehicle Identification Number: 1Z37L2S523822
1 = Chevrolet Division
Z = Corvette
37 = Coupe
L = LT1 engine
2 = 1972
S = St. Louis plant assembly
523822 = Production sequence number (during the month of May 1972 Corvette units 22611 through 25225 were produced)

Trim Tag:
Body - K14 = Built June 14, 1972
Trim - 400 = Vinyl black
Color - 912 = Sunflower yellow

Engine Stamp Pad:
V0421CKY 12S523822
V = Flint Plant
0421 - Date Code = April 21 (engine assembly date)
CKY = 4 speed, mechanical lifters, Holley 4BBL
12S523822 - 1 = Chevrolet, 2 = 1972, S = St Louis, 523822 = production sequence number

Block:
3970010 - 4 bolt main
Date code: D82 - D = April, 8 = 8th day, 2 = 1972

Transmission:
VIN (Vehicle Identification Number): L2S523822
Main case part number: 3925661
Extension (tail) part number: 3978764
Side cover part number: 3952648
Code: P2E19A
P = Muncie 4-speed
2 = 1972
E19 = May 19th
A = 2.52:1 - First gear - wide ratio

Rear:
AAW143 1E
AA = 3.55:1 Corvette positraction axle
W = Warren, MI plant
143 = Day of year: May 22, 1972
1 = Shift
E = Positraction Source: Eaton

Alternator:
11 00544 61 - 1972 Delcotron 61 Amp Alternator - with A/C
12VNEG = 12 Volt - negative ground
Date Code: 2E17 - 2 = 1972, E = May, 17 = 17TH day

Carburetor:
Holley 4150 - with standard transmission
Carb list # R 6239-1
Date Code: 244 - 2 = 1972, 4 = April, 4 = 4th Week

Starter:
1108418 - 1972 Corvette 350/255HP with manual transmission
Date Code: 2D26 - 2 = 1972, D = April, 26 = 26th day

Intake Manifold:
3959594 -1972 Corvette 350/255HP
(note: date code is under the oil splash shield on the under side of the manifold. The shield, if removed will be damaged.

Exhaust Manifolds:
Front side:
Left - 3932461, RH6
Right - 3932461, RH6
Back side:
Left - date code: E17 - E = May, 17 = 17th day
Right - date code: E12 - E = May, 12 = 12th day

Distributor:
1112101 - 350/255HP / LT1
Date Code: 2E18 - 2 = 1972, E = May, 18 = 18th day

Heads:
3973487X - This head is identical to 397387. The 3973487X was used only on late 1972 models.
Date Code: Left - C62 - C = March, 6 = 6th day, 2 = 1972
Date Code: Right - C142 - C = March, 14 =14th day, 2 = 1972

Value Covers:
Left hand - 3989005
Right hand - 3965542

Master Cylinder:
5480346
Stamping on flat ground area: PG

Seat Belts:
Driver & passenger lap belt - model C-15
Date Code: 1-E-72 - 1 = week, E = day (Friday), 72 = 1972
Driver & passenger shoulder belt - model C-25
Date Code 1-F-72 - 1 = week, F = day (Saturday), 72 = 1972

Wheels:
K 1 3 3 (v)*1 AZ -------------- K 1 2 5 (v)* 1 7 AZ (spare)
K = Kelsey Hayes ------------- K = Kelsey Hayes
1 = Romulus Plant ------------ 1 = Romulus Plant
3 = 1973 ------------------------- 2 = 1972 (spare)
3 = March ------------------------5 = May
1 = 1st day -----------------------17 = 17th day
AZ = Corvette (15X8) -------- AZ = Corvette (15X8)

* (v = valve stem hole)

LOF Glass:
Left side:
Soft-Ray
Safety AS2
Solid tempered
DOT 15
M74
Flo-lite
Dated Code: JY = May 1972

Right side:
Soft-Ray
Safety AS2
Solid tempered
DOT 15
M54
Flo-lite
Dated Code: JY = May 1972

Windshield:
Shaded
Soft-Ray
Safety AS1
Laminated
DOT 15
M24
Flo-lite
Windshield
Date Code: IY = June 1972

I have also attached a couple pictures of one of the heads showing the valve train and one of the valves with mic showing the size of the intake valve.

I know this is long and spread out, but I would like to get some feed back from others. I have been emailing back and forth with Joe Lucia and we concluded the heads are an aberration. Given the dates and casting numbers I am confident the heads are original the car.

Your comments.

[William C.]

Re: 1972 Lt1 w/press-in studs and 2.02/1.94 valves

For starters, try measuring the exhaust valve again, with a 2.02 intake, which is correct for the engine you can't get a 1.94 exhaust in the head. Depending on how late the car is, the screw in studs were discontinued in the 73 model year so that could have been a running change or???

[Jerome P.]

Re: 1972 Lt1 w/press-in studs and 2.02/1.60 valves

Bill Thanks for your comments. I was not thinking when I posted initially. The 1.94 valve size is the intake valve size on the standard 350 engine. My mistake, I know better. I have edited the texted of my first post; corrrecting the error.

I did measure the exhaust valves and just didn't memtion it. They do measure correctly at 1.60"

It is possible like you said, the heads maybe for the 73 model year. The car is a June 14th built vehicle.

Are you sure that they discontinued the screw-in studs with the '73 model year?

Any follow-up will be appreciated.

Thanks

[Joe L.]

Re: 1972 Lt1 w/press-in studs and 2.02/1.94 valves

For starters, try measuring the exhaust valve again, with a 2.02 intake, which is correct for the engine you can't get a 1.94 exhaust in the head. Depending on how late the car is, the screw in studs were discontinued in the 73 model year so that could have been a running change or???

Bill-----


I believe that L-82, first available for the 1973 model year, used screw-in studs through its last year of production in 1980. So, I think these late 1972 LT-1 heads of Jerry's amount to some sort of "aberration".

[Patrick H.]

Re: 1972 Lt1 w/press-in studs and 2.02/1.94 valves

Slightly different topic...

Nice numbers, but would you also happen to know your water pump?
See thread:
https://www.forums.ncrs.org/showthre...71288&uid=9382

Patrick

[Jerome P.]

Re: 1972 Lt1 w/press-in studs and 2.02/1.94 valves

Pat, I have the car at the garage. Next visit I will get the number. Probably in a couple of days.

[William C.]

Re: 1972 Lt1 w/press-in studs and 2.02/1.94 valves

My error, should have checked the parts book, SHP kept the screw in studs at least thru 1980 according to the parts book.

[Patrick H.]

Re: 1972 Lt1 w/press-in studs and 2.02/1.94 valves

Next question is... what head gaskets were on the motor when these heads were removed? If they were the original steel shim type, that would go a long way toward establishing them as "likely original." If the gaskets were of another type, then anything could be possible.

One of the heads on my 71 cracked, and I bought a date matched set for the car. No reason someone couldn't have done the same for this car.

Patrick

[Joe L.]

Re: 1972 Lt1 w/press-in studs and 2.02/1.94 valves

My error, should have checked the parts book, SHP kept the screw in studs at least thru 1980 according to the parts book.

Bill----


The P&A Catalogs could be incorrect on something like this. However, I cross-checked with several other references as well as my own personal experience with L-82's to confirm that screw-in studs were used on all L-82's.

[Clem Z.]

Re: 1972 Lt1 w/press-in studs and 2.02/1.94 valves

the fact the heads are painted inside the valve spring area and it had composition head gaskets leaves me to believe it is not cherry

[Bryan M.]

Re: 1972 Lt1 w/press-in studs and 2.02/1.94 valves

I pulled the oil plug out of the driver-side valve cover on my 1972 LT-1 with a/c to take a peek and found the screw in studs. It's a April 27 build date and the head is a 3973487X with a date code of C2 2.

[John P.]

Re: 1972 Lt1 w/press-in studs and 2.02/1.94 valves

Point of reference: Have knowledge of a 72 LT1 air coupe, ser# 22741, build date 6-2-72. Heads have screw in studs and guide plates. Built only 2 weeks before your ser#.

[Greg Y.]

Re: 1972 Lt1 w/press-in studs and 2.02/1.94 valves

If it helps, I have a 72 A/C LT1 coupe vin 23827 build date K14 and a 72 LT1 convertible build date H22 and both have screw in studs and guide plates.

[Terry M.]

Re: 1972 Lt1 w/press-in studs and 2.02/1.94 valves

The fact that your heads have painted valve springs doesn't tell us much. The WAY they are painted tells us everything. See the attached 6000 mile 1972 LT1 heads for the original paint pattern.

Well you guys won't get to see the original mask pattern for the exhaust ports and spark plug ports because the board says I followed an invalid link -- after waiting five minutes for the first picture to load. Your loss.

Edit add: one more try: Screw it.

[Chuck S.]

Re: 1972 Lt1 w/press-in studs and 2.02/1.94 valves

...after waiting five minutes for the first picture to load. Your loss.

Edit add: one more try: Screw it.

Awww...Com'n, Terry...At least give us a clue as to what the pictures "say".

I believe the TIM&JG(?) says optional engines with aluminum valve covers were painted with stamped steel covers in place, and that these were reclaimed and used again for the same purpose.

Clearly, there were no valve covers in place when the heads were painted, but there does appear to have been an effort to mask the valve area with something that extended from one end of the head to the other. Paint overspray on the upper and lower periphery of Jerome's valve area is light as might be expected for a factory paint job.

Factory, or...??