The Fel-Pro Performance PN 1125 head gaskets have 4.385-inch bores and a 0.041-inch compressed thickness.Work those numbers with the 70cc chambers in the iron heads used this month and the compression ratio is just 8.77:1.
The only nonstock components in the short-block are ARP rod bolts and Speed-Pro forged pistons, PN L2353F, in a 0.030-inch overbore (stock bore is 4.3125, so our bore is 4.3425 for 462 ci).
The Speed-Pro slugs are the lowest-priced forged pistons you can buy for the 455; TA Performance sells them for $429.95 a set.
That’s an opinion long held at CC dating back to the time we swapped an old Electra 225 motor into a Skylark wagon for summer fun, and then again when the Buick beat all comers in the now legendary CC shootout of all the GM corporate big-blocks.
Sadly, the state of gearhead living has changed drastically over the last five years, and even here in So Cal, the Buick 455 engine donors just aren’t in the ‘yards or on the streets like they used to be.
In fact, when Editor Glad did finally score a junkyard 455 while planning for this latest Buick story, the block turned out to be damaged beyond repair.
Instead, the engine core we used came from the voice of the industry, Dave Mc Clelland, who keeps a few in stock to feed his original ’70 GS455 four-speed convertible.
Small Cam, Dual-Plane Intakes Our first round of dyno tests used the TA Performance hydraulic flat-tappet cam known as the TA-212.
It specs out at a tame 218/230 degrees of duration at 0.050 tappet lift.
The ’75 to ’76 castings have factory 78cc chambers and are never used by TA.
The ’70 heads are 68 cc, and the ’71 to ’74 units have 71cc chambers that are milled to 69 to 70 cc during the rebuild process.
The headers are for a Skylark, feature 1 7/8-inch primaries and 3-inch collectors, and were run with 18-inch collector extensions.