That short stroke is the key -- the 232 gains a lot of torque, but loses 1000 rpm and 20 hp. The 258 is even worse, lots of torque, but HP peak moves down to 4000.
The drop in peak HP-rpms is easily solved : bigger camshaft...
Been doing a bit of soul-searching with a dyno-program myself,saves some money to change cams and so on in the program instead if buying parts You think will be good for Your motor,bring it home put it in and find out that it's no good...
Go out by another one try again,that can be a money-pit big way.
But back to camshaft vs engine-size:I took the cam-card of a Crane camshaft and "built" 4 engines N/A with the same intake,carb and exhaust ,comp-ratio varied since a stroker was involved but none was a hi-comp engine(9.0-9.6).
A 4.0 liter with 9.0 comp peaked it's HP @ 6000 rpm,the 258 landed @ 5250 rpm and the stroker @ 4500,then I tried a destroked
258 0.060 overbore with a 4.0 crank/rods (around 226 cu in "baaad memory,and soon bedtime"...)the peak ended up @ almost 7000 something rpm of course it lost both hp and tq but on the other end it kept the HP up much longer "8500 rpm" The stroker fell flat on it's face @ 5000 and at 5500 it was absolutely dead.
This was with a Hyd. cam 216/228 @ .050 lift (112 deg lobe-separation angle) and to get the same peak rpm on the stroker You will probably have to get a camshaft with 15-20 more degrees duration,maybe even more than that,haven't tried that out yet.
Well enough for now it's time to go and take a talk with the pillow,up to work in 5 hours It's almost midnight here now but then it's Friday and a free weekend...
All the best : Speed Swede
