so i'm rebuilding my original 1970 340

@273
You get 22 mpg now, how much more can you possible get and what really $$$$ savings would that get you, what do you spend on gas a year now $500, $1000, $2000? even if you could save 10% on $2000 is only $200 a year. If you do a lot of Highway install an OD tranny but I wouldn't neuter the performance too much for a couple more mpg's.
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I DID GET 22mp with the engine that was stolen , now getting about 15 mpg with the 426 stroker in the car now getting expensive with 3 gallons of 110 octane with every 10 of piss .i just want something fun to drive , that revs quickly and gets good mpg . don't do much city driving mostly higway and back roads. f I want fast I'll put the stroker back in
this is just a project to see if it can be done and to keep busy. As for cam i think a mild roler with good amount of lift and not much duration should do fine , not impressed with lopey cams want good all around performance with max hp around 6200 - 6400


If your looking to make peak power around 6200-6400 rpm with a 340 my guess that's about 450 hp. If your trying to build with good mileage and driveablity I do it like how LS and modern hemi's do it lots of head air flow and mild roller cam. Normally most would use 240-260 cfm head with 10.5:1 and a 285 ish cam to reach your power goal, I'd go with at least 280-300+ cfm heads with high rocker ratios to put you in the heads air flow sweet spot and keep the duration relatively small, once you decided on heads I'd play with different cam timings in a dyno program.