The LS-series are good motors, but for a second gen 'Bird I'd stay with pure Poncho power- less high tech but cooler and old school. I'm building a 455 for my '72 Bird this summer, but if I didn't get that 455 I would have built a 400/462 stroker out of a 400 2-bolt block, and put the 4-bolt splayed caps on it.
The big advantage with the stroker is the 4.25/3.0/6.8 combo lets you rev it faster than the 4.21/3.25/6.625 combo in a stock 455. The stroker is also alot easier on the bearings and stronger than the 455 in the main web area. Add a forged crank and aftermarket 4-bolt splayed caps and you can buzz that mill to 6500 all day. Of course you need to have heads that can use the RPM- some 310 cfm KRE's or wideport E-heads would do the job nicely. Add a solid roller and you're making 600+ hp/ 575+ ft-lbs on pump gas.
Geno
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