340 or 408?

67_Slimer said
THIS is what I wanted to hear. Thank you , Having the 360 block ready to go , I don't have to get taken on a 340 block. Thank you. Would like to get 500-550 hp out of it with my current top end and 11/1 compression. Looking into solid roller as well. Ant info or recommendations are appreciated! Thank You.

If shooting for more like 550 hp your probably gonna need some sort of stroker not that a 340 can't make 550 hp just most of that gain gonna be 5500-7000 + rpms at least you have 4.56 gears but the higher rpms you make the power at the harder it is to get into the powerband at normal road speeds 20-50 mph.

Peak power doesn't matter so much on the street, the gearing for your car is fixed so that means the rpms at normal road speeds through the gears is fix, say at 10-80 mph through the first few gears, Eg.. say were generally talking 3000-6000 rpm is the range you spend most of your time at full/heavy throttle, that's where you want most of your gains doesn't mean you want your engine to peak in 3000-6000 rpm range an engine that peaks at 6500 rpm probably have better 4000-6000 rpm than a engine that peaks at 6000 rpm.

Your the designer/engineer your designing/modifying to make the powerband work the way you want/like.

The 340 guy's are gonna recommend 340 and 408 guy's are gonna recommend 408 etc..

Where is you car weak where do you want it stronger ? If the bottom end is fine and you want a lot more top end 5500-7000 rpm probably don't need a stroker or much of one (3.58" might do).

Seem like you got a decent 340 bottom end, maybe just upgrade to Trick Flows or port the Eddie's on the engine you got and if you find you need more bottom end power then go stroker. Would be the way I'd do it, make decisions off baseline results instead of shots in the dark.