Quote:
Originally Posted by cobalt327
Brodix says no steam holes. Period. That was confirmed to me some time ago. What is being talked about are the head gasket/block coolant passages, in some cases they don't line up as well as they could and need to be located better. There are also things to look out for on the head gaskets, as shown here: Small Block 400 Cooling Tricks.
FWIW, Joe Sherman doesn't use them. But he'll gladly do them for others. For a fee, of course.
As far as a 325 hp 10.25:1 sbc LS3 2bbl 400,  I'll have to pass on that one. lol Except to say the only engine I know of that comes close to that was a 402 BBC. Another odd engine was the 265 hp bbc 396/ 2bbl.
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This 400sbc was not a 2bbl engine. It was a factory 4bbl engine with factory flat top pistons and the 487X heads with factory 1.94x 1.60 valves.
The 487X head had a slightly larger intake port and probabily the best exhaust port of the like heads. It was factory rated at 330HP and was a true 10.25:1cr
It was only offered in the 1970 Impala. (I had seen these 400's in the Impala before and when the opportunity came up to buy one, I did. I bought the whole car. I knew exactly what it was, when I bought it.)
if you search a bit you will find mention of it.
It is mentioned in the larger versions of the Motors Manual and in the book Fix your Chevrolet. I got this stock 400 -330hp 10.25:1cr motor out of a used 1970 Impala. It made real good power in my 68 chevelle. Only the 454 I built and ran back then ran faster.
This was no 265Hp 2bbl motor. I installed Z/28 valve springs to get more rpm butr never cammed it.
I disassembled it after the block froze up. All stock GM internal parts. As stated.
I had a stock intake-and Qjet and a Edelbrock street master-750VS on it and headers and GM Z/28 valve springs. All else was stock GM. The stock GM springs were tired and it would not rev over 4500rpm with them.
It would rattle like a pig if you tried to use regular gas. Was not a big rever (stock cam) but pulled like a freight train.
These factory high compression ratio OEM 400 4bbl engines existed, just not widely known of especially by those that were not there at the time.
A friend here had one of those factory odd ball 2bbl 396 motors a 1969 chevelle w powerglide.