Thread: Intake swap

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Nice looking truck!


".....Wouldn't the dual quad wcfb's they ran in 56/57 flow as much fuel as a 625 cfm demon?...."

While a pair of WCFBs will potentially flow as much or more than the Demon, as the link Roger posted says, most have have a secondary air valve that effectively prevents the secondary from operating until sufficient vacume is created to open them.

"......I'm looking at some of the power pack heads 3731539. These were used on the '57 283-283 hp engines. Will these work on my 265 with stock pistons ya think?....."

Depending on the source book you read, those heads are 59 or 60CC chambers and if your running stock compression (8.5) with the low performance heads they should move you up to a bit over 9:1-9,25:1. There were several other casting numbers used on the PP heads (the ones with the pyramid) over the years, but the later ones would have the valve cover bolt holes that are straight across.


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If I remember correctly, the 283 I had in my '59 Impala had the lower compression head that came with the 2 bbl carburetor which was 8.5:1 compression. By swapping to a power pack head, it raised the compression to 9.5:1. Feel free to correct me if my memory of an event 47 years ago is incorrect.