found out what my big block is tonight

[sweetk30]

i have a bbc i have had for a few years. runs good and just needs a little clean up. picked it up for 500 bucks.

well got it out of the truck tonight after 3-4 years. then run the casting #'s its a 8-1972 402 bbc .

not sure what to put it in. need to plan this out. i am thinking my plow truck.

edit :

to515ctb 12j272447 front pad info

6272292 heads

3999290 block

6263758 intake

all with 72 date codes.

4x4high scott is getting me some info monday at work.

 

[3 on the tree]

i have a bbc i have had for a few years. runs good and just needs a little clean up. picked it up for 500 bucks.

well got it out of the truck tonight after 3-4 years. then run the casting #'s its a 8-1972 402 bbc .

not sure what to put it in. need to plan this out. i am thinking my plow truck.

I think it needs hardened seats, and exhaust valves, to live on unleaded. I burnt a seat, in my 70, cause I ran a couple of tanks of gas w/o the lead substitute.

 

[ryoken]

which heads are on it?

many 396's from the factory where actually 402's.. They just didn't want to rebadge em...

 

[b454rat]

Wow what is it with 402s all of a sudden?? Never hear of them, then they pop up all over. I picked one up, same year at a yard. Gonna sell and run the 454....

 

[82355]

Wow what is it with 402s all of a sudden?? Never hear of them,

Because they were badged as 396's and 400's for some odd reason.

Martin

 

[pauly383]

Because they were badged as 396's and 400's for some odd reason.

Martin

It was brand recognition with the SS396 that caused the 402 to be called a 396 . People were buying Chevelles with 396's and they didn't want to mess up a good thing .

The 400 thing was just about saving money . Two engines close to each other size wise for pedestrian cars like the Impala and Caprice , and the trucks ( 400 sb , 402bb ) . ONE set of emblems needed to build either car or truck

 

[ryoken]

I've been surprised over the years to learn how many 396's where actually 402's.. far more than I thought...

my bud had a 72 back in the day that was actually badged as a 402... my 69 was a true 396, which I promptly punched to 402 anyway...

 

[Stomis]

yeah 402s werent even done on purpose or so i've read. A load of blocks were just punched over by mistake and instead of loosing out on the money they used them.

 

[3 on the tree]

I read somewhere, that the overbore was to partially make up for power losses related to increased emissions requirements. Many years ago, I had a 72 3/4 ton Burb with 400 badges, and a 4 speed. The motor was actually a 402. My dad used to own a mid 70s GMC K1500. It too, had 400 badges, but the engine was a 400 small block. I think that 69 was the last year for the true 396 motor.

 

[sweetk30]

more info at the top now with casting #'s

 

[b454rat]

What does it say up front, but the alternator???

 

[Greg72]

which heads are on it?

many 396's from the factory where actually 402's.. They just didn't want to rebadge em...

IIRC, the difference between a 396 and a 402 is a measly .030" overbore... you can be sure that most of the original 396s have probably been bored like that to clean up the block by now.

The original "396" in my K5 turned out to be a 402 when it finally was torn down for a rebuild.

I don't think there's any way to differentiate them by casting numbers either. Mortec.com site decodes them as 396/402 but doesn't get more specific than that.

 

[joecowap]

I think I remember reading somewhere that the storage warehouse where the 396 blocks were got flooded, and rather than scrap all the blocks they bored them out.