I had these at Homecoming and someone pointed this out to me. He (and I) have never noticed this before. Both are originals but I do not know what year each came from. I know some of the ones I have are from 70 and some are from 72. I only have one with the short tabs. Does anyone know what the difference is or what year they changed?

 

Interesting observation.
Which is 1970? IIRC these 4 core top plates were different in pre 70 and post 72 models so what you have must be 70-72. How does the one in your 70 442 compare?

When I looked at pic 2, I wondered if someone hadn't modified that upper plate. The 'cut line' doesn't look like a factory stamping - which these were all formed from. You're in a better position to see and describe it.

 

One of these are from my 442 but I do not know what one.

The picture don't show it well but the hole for the rubber tab is higher. It would require a differant rubber insert for the tabs to fit correct. I think I have the rubber inserts to both of them. I will see if the rubber part has differant part numbers. (if the rubber has the number molded in them)

 

If the rubber mount is up higher, the rubber insert from a 3 core might fit.

 

Bingo!
I just located the ones i took out of them. The one that fits is the same number found in a 3 core top plate and the deeper ones have there own part number. The part number for the 4 core only, also have a 69 molded on them. If that is a year I wonder if they made the change later (maybe 72) to be able to make only one rubber for both applications?

 

Just looked at a picture I have on a 72 W-30 I had. I know for a fact this top plate is original to the car. It is hard to tell but I think it is the shorter style?

 

I have the same pair of top plates & have only owned one '69-'72 442 - so I don't know where or what these came from. I did post the same question here a couple years ago, but it died a slow unanswered death.

 

My early 70 build 442 has the long tabs - I had a 71 cutlass for a while and if I remember it had the short tabs

 

I have two three core top plates. One has long tabs and one has short very similar to what's pictured. When I first noticed the difference I thought one was for a four core but they fit the same size tank. I'm 99% sure the long tab one came on my Fremont built 70 and the short tab one was from ebay off an unknown year.

 

Looked at one of my 4 core top plates this afternoon. I am almost certain it is originally from a 70 W-30. It has the longer tabs.

Don W

 

My '69 (W31) four core, has the long style shown on top.

 

Does anyone have a known original to a 72 they can compare to?

 

Which one is available reproduction?

 

group 1.270 of the parts catalogs & section 11 of the assembly manuals
RADIATOR SUPPORT UPPER:
1967 = 391429 - uses (4) INSULATOR 391321
1968 = 400824 (V01, C60, Y72) - uses (4) INSULATOR 391320
1969 = 403029 (V01, C60, Y72) - uses (4) INSULATOR 391320
1970 = 403029 (V01, C60, Y72) - uses (4) INSULATOR 391320
1971 = 407120 (V01, C60, Y72) - uses INSULATOR (2) RH 407122 & (2) LH 411229 - radiator has a 3 row & a 4 row tank
1972 = 407116 (C60) - uses (4) INSULATOR 407117 - 3 row radiator
1972 = 407120 (Y72) - uses INSULATOR (2) RH 407122 & (2) LH 411229 - radiator has a 3 row & a 4 row tank


My '68 H/O has the longer "cut on an angle" saddles to hold the radiator - pic below I believe is correct for 442 as some '71-'72 a-bodies used a 3-row for A/C cars.

 

Some pics of insulators off eBay & you can see the wide saddle & thicker to the front insulator in this '72 that was pictured above. I don't put too much faith in the dimensions shown, I have an original 391321 in my hand & the dimensions don't quite match.

 

The core support/top plate/insulators page from the 1970 assembly manual at "WILD ABOUT CARS"
I understand that paperwork and actual car builds varied, but I don't believe the 391321 "insulators" will properly fit the 403029 "upper baffle" (LH or RH).

 

The long tabs are for 69-70 and the shorter are for 71-72. I researched thus a few years ago and it was this way on every car I looked at at the time. Even the cradles welded to the bottom of the radiator support are this way, even in the big cars.

 

good pics eric

 

bump

 

Thanks to everyone for the information. Another interesting fact that I never knew, which is why this "hobby" is so fascinating. Always learning something new. Wonder why Oldsmobile changed these parts over the four years, especially since the overall design did not change?