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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 9.95 a set.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 compression height is 1.975, the stock rods are 6.600 inches, the stock stroke is 3.900 inches, and the production deck height is 10.57 inches.That adds up to pistons that are 0.045 in the hole, but JMS decked the block 0.005, so the real-world number is a poor 0.040 below the deck.For just an extra 5 to 0, you could get modern, lightweight, custom forgings with 1/16-inch rings, and the extra money could be well worth the opportunity for more compression.The Buick 455s were launched in 1970 with 10.0:1 to 10.5:1 compression, but that fell to 8.5:1 in 1971 and then to 8.3:1 before the engine was discontinued after the ’76 model year.

We’ll give you the dyno-proven power using multiple combinations of two cams, four intakes, and three sets of heads.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. 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.However, they do have some drawbacks, including an old-school 5/64-inch ring pack and a hefty 758-gram weight.

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