Hello, This is just plain weird, 396 ,1969,Block 3955272, Stamped T0131J0. The restoration book i have indicates that that block stamping was for the 402 ci 396, also that it also came with the L78 option. Yet when i looked up the id code on nastyz's they indicate that the J0 suffix was a 396 police. whatever that means. any help would be appreciated. Thanks

The only JO I can come up with is (69, impala, 396/265hp, 2bbl, 9.0:1 comp.)

396 Police refers to the application. The police package was the low compression, 2-bbl 396/265 hp only available in cop cars I believe.

The block came in both 2-bolt and 4-bolt versions and used in 265hp passenger car, all 3 Chevelle and Camaro hp engines, plus 350 & 375 Novas. So, while the restration book you have isn't incorrect it's very much incomplete if it only notes it as an L78.

My old vintage Chilton calls it a 396 TH400 2 barrel POLICE...

The GM parts catalog for this era also states the suffix JO is for a 1969 396 (Police) 2-bbl carb 3-speed auto trans (TH400). RPO L66

When the 402 was introduced mid year 69, they went to a "3" digit suffix. "JO" would be pre-402 introduction.

Alan Colvin also lists it as a 69 Passenger 396/265HP Police.

There is no "CJO" listed in 1970 so this application also ended prior to 402 implementation. Likely due to the 454 introduction in the large, Passenger cars.

While the block's "Casting number" Can be used in multiple applications, the Tonawanda "Suffiix Stamp" clearly identifies which application it was originally used.

The same confusion often applies to the 512 Block. While people often associate this block with the 1969 COPO, 427's and the 1970 LS6 454's, it was also used in low Horse, passenger, 1969, 2 bolt, 335HP 427's.

The Suffix stamp, tells the true story of the engines original application, not the casting number.

My info echo's the groups:

JO 69 396 Impala 265 L-66 TH-400 2-Brl Police

JO is correct for the 69 396 police motor, I have one with the two barrel and raised manifold. Strange looking with a two barrel on it. If im not mistaken its been awhile since i have looked at, but Im thinking its a 4 bolt block, by looking at the oil filter housing area. Not sure though.

It probably is JQ, 396 TH400 non police. I have seen JQ get mistaken for JO several times. Is there a vin stamped on the engine pad or down by the oil filter? If so, what is it?

It probably is JQ, 396 TH400 non police. I have seen JQ get mistaken for JO several times. Is there a vin stamped on the engine pad or down by the oil filter? If so, what is it?

I am in a different local then where my car is but i will check it when i get the chance and get back to you.