"EX87" just sold on BaT for $320,000

[Duke W.]

Interesting story... Is it all true? The bidding was furious!

https://bringatrailer.com/listing/ch...ign=2025-05-19

Duke

[Duke W.]

I've just gone through all the comments and information provided by the seller and have a few questions that maybe others can help sort out.

At some point (sixties?) a new 327 short block was installed. One commenter asked for some block and component casting data, but unless I missed it we only got a block cast date, E106 (May 10, 1966), but not a block casting number

In that era there would have been two 327 short blocks, one for SHP/FI and one for 250/300 HP engines. Early on the SHP/FI short blocks would have had the Duntov cam and forged/doomed pistons. At some point a 350 HP short block would have been added with the ...151 cam, but what about the mechanical lifter blocks. Did one with a 30-30 cam replace the one with the Duntov cam or were both offered in the '66 time period?

Of course, all of the above short block configurations would most likely be ...870 blocks.

The head casting photo shows 373165?, but the closest number I see in the NCRS Spec. Guide is 3731762. Did passenger car small blocks use any other castings? IIRC they were described as "'56 power pack" heads.

Even if the short block has the base hydraulic lifter cam the CR would have been awfully high. The small port heads used on the 327/250 were specific castings for 327s with larger chambers (nominally 61 cc like the 461X heads) because the smaller chamber 265/283 heads would have resulted in too high compression at the same deck clearance with notched flattop piston with the valve clearance notches due to the increased stroke. (All other things equal including deck clearance and crown design, increasing stroke increases CR.)

Use of the SHP/FI short block likely would have resulted in piston-head interference and even if not, the CR would have been way too high for even the best pump gas of the sixties era.

Then there is the inlet manifold. A number beginning with 38 is way too early for the mid-fifties even though the NCRS Spec Guide lists 3837109 as "possible usage" for '56 210 horsepower. Maybe this comment is due to NCRS observation of this car in Flight judging back in the seventies. I don't see any later usage of this manifold in the NCRS Spec. Guide. Could it have been used on later pass. car small blocks?

Maybe Joe Lucia and give us the history and usage of this casting number,

Duke

[David H.]

I've just gone through all the comments ... ... Then there is the inlet manifold. A number beginning with 38 is way too early for the mid-fifties even though the NCRS Spec Guide lists 3837109 as "possible usage". Maybe this comment is due to NCRS observation of this car in Flight judging back in the seventies. I don't see any later usage of this manifold in the NCRS Spec. Guide. Could it have been used on later pass. car small blocks? ... Duke

Duke

1956-57 TIMJG shows 3837109 as (early) for 1956 210hp usage.

Nothing noted in TIMJG as to when early/late broke for this part.

Dave

[Duke W.]

Yes, but the biggest problem is that 1956 is too early for any part numbers that start with 38 to be released. At least that's been my long held belief, but maybe I'm wrong. Joe Lucia might be able to resolve this since he can ferret out part number histories, at least for end item released parts, but since this is a casting number and the finish machined manifold probably has a different number he may not be able to sort it out.

As far as inlet manifolds are concerned, the first casting number beginning with 38 is for '63 models. Thumbing through the 1953-67 NCRS Spec. Guide I also see a couple of "38" casting number for 53-55 exhaust manifolds, but the next occurrence of a 38 exhaust manifold casting number is '65. I also see 38 casting numbers for '53-'55 six-cylinder blocks, so maybe the central foundry began using casting numbers beginning with 38 in 1953, which blows my long held theory that 38 number didn't start until the early sixties.

Duke

[Michael J.]

Seems to me, I used to hear Loren Lundberg talk about this V8 test mule car.

[Joe L.]

Yes, but the biggest problem is that 1956 is too early for any part numbers that start with 38 to be released. At least that's been my long held belief, but maybe I'm wrong. Joe Lucia might be able to resolve this since he can ferret out part number histories, at least for end item released parts, but since this is a casting number and the finish machined manifold probably has a different number he may not be able to sort it out.

As far as inlet manifolds are concerned, the first casting number beginning with 38 is for '63 models. Thumbing through the 1953-67 NCRS Spec. Guide I also see a couple of "38" casting number for 53-55 exhaust manifolds, but the next occurrence of a 38 exhaust manifold casting number is '65. I also see 38 casting numbers for '53-'55 six-cylinder blocks, so maybe the central foundry began using casting numbers beginning with 38 in 1953, which blows my long held theory that 38 number didn't start until the early sixties.

Duke

Duke------


Casting numbers and finished part numbers in the 3835xxx, 3836xxx, and 3837xxx series were released in the early to mid 50's period. However, all that I am familiar with were engine-related parts. Otherwise, 38xxxxx series part numbers were first issued in the 1962-63 period.

Why the 50's out-of-sequence use of the 3835xxx, 3836xxx, and 3837xxx occurred I do not know. There must have been a reason for it but it's "lost in antiquity" as any of those that knew the story are likely all gone now.

[Joe L.]

I've just gone through all the comments and information provided by the seller and have a few questions that maybe others can help sort out.

At some point (sixties?) a new 327 short block was installed. One commenter asked for some block and component casting data, but unless I missed it we only got a block cast date, E106 (May 10, 1966), but not a block casting number

In that era there would have been two 327 short blocks, one for SHP/FI and one for 250/300 HP engines. Early on the SHP/FI short blocks would have had the Duntov cam and forged/doomed pistons. At some point a 350 HP short block would have been added with the ...151 cam, but what about the mechanical lifter blocks. Did one with a 30-30 cam replace the one with the Duntov cam or were both offered in the '66 time period?

Of course, all of the above short block configurations would most likely be ...870 blocks.

The head casting photo shows 373165?, but the closest number I see in the NCRS Spec. Guide is 3731762. Did passenger car small blocks use any other castings? IIRC they were described as "'56 power pack" heads.

Even if the short block has the base hydraulic lifter cam the CR would have been awfully high. The small port heads used on the 327/250 were specific castings for 327s with larger chambers (nominally 61 cc like the 461X heads) because the smaller chamber 265/283 heads would have resulted in too high compression at the same deck clearance with notched flattop piston with the valve clearance notches due to the increased stroke. (All other things equal including deck clearance and crown design, increasing stroke increases CR.)

Use of the SHP/FI short block likely would have resulted in piston-head interference and even if not, the CR would have been way too high for even the best pump gas of the sixties era.

Then there is the inlet manifold. A number beginning with 38 is way too early for the mid-fifties even though the NCRS Spec Guide lists 3837109 as "possible usage" for '56 210 horsepower. Maybe this comment is due to NCRS observation of this car in Flight judging back in the seventies. I don't see any later usage of this manifold in the NCRS Spec. Guide. Could it have been used on later pass. car small blocks?

Maybe Joe Lucia and give us the history and usage of this casting number,

Duke

Duke------

There was no head casting of 373165x that I can find. However, there were several heads of 3731xxx so I suppose it is possible that it could have existed.

I also cannot find any information on a 3837109 casting number. However, there was a 3837064 that was used on 1956-57 passenger cars and trucks.

[David B.]

I am very familiar with EX-87 and the story behind it. Had many conversations with Loren over the car but we never could quite agree. Our relationship started with an article I wrote for the 1985 spring edition of the RESTORER (vol. 11 #4). At the time I had obtained significant information from GM Engineer Frank Burrell who had transported valve stem sealing options to Phoenix in late 1955 to assist Duntov in planned testing. The Engineering document shown I obtained from Frank along with a significant amount of other material relating to that car and the 56 Corvettes Ed Cole planned to race at Sebring. EX-87 started out as a ride demonstrator for Engineering personal. I believe it was originally a new '54. Have files somewhere, the full story is really interesting.