Thread: block number

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Yep stock 390 stroke is 3.78" so your about right with your measurement. The intake is std issue 4bbl for a 65 352/390. Not a bad intake but heavy.

Then I wonder why there are 406 stickers on the valve covers and air filter, weird huh?

Well it could be a 428 block with a 4.13 bore and a 3.78 stroke. It's not an original 406 they were a 62.5 to 63.5 option only. And the blocks were a little different from the 428. But displacement wise you'd be a 406 with that combo. Or it's wishfull thinking on someone's part. Like putting a 427 sticker on a 390 if you will. If the stickers are round and gold, with black and white lettering/numbers they are original or original style repops. "406 High Performance" is what they would say. The valve covers from the 406's were chrome baldies. Worth a few $$$$ if so. Until you get around to pulling a head off it's a mystery......

Well, i'm planing on pulling off a head this winter so the mystery will be short lived.

Well cool! Give us an update what you find. Good luck!