340 Rebuild "Musts"

For a 400hp 340 build I would use stock crank and rods. Have rods resized and run good bolts. Extra mile on rods would be flash ground and shot peened. Have deck surface cleaned up and squared. My big block took .005 to clean up. I would run a forged budget piston and aim for 9.2-9.6:1 compression with iron head. Slightly aggressive solid lifter cam in the 240@ .050 range. Eddy performer rpm intake. Set of j or x heads with mild bowl work and decent valve job. A 750 Holley carb. Set of 1 3/4" headers into a 2.5" duel exhaust setup. Things like wind age tray are free hp. A good balance job is a must! Get timing at about 18-22* initial, 33-36 total and all in by 2000rpm and your gonna have s fun setup. I'd also run stock mechanical rocker arms. This setup leaves room for improvements down the road but still loads of fun.