It depends... on the crank and casting but you can get a 308 or 310 in with very minimal clearancing.. you can run ratio roller rockers or billets on the big cams .. not stamped the spring pressure you will need will eat them up . Not going to benefit from a cam that big without a good head though .. its more about the combo that works well together than just throwing a big cam at it
Trink is right...
Depends what the head flows and the carb together also...
I have built motor with a mild port and polish, 27/24 valve head, 390 carb, 308 cam with Champ rockers fly!!!
I have also built a motor with a good port and polish, 32/28 valve head, 360 Tilly, 310 cam with 1.3/1.2 rockers and it flies...
Also built a motor with a decent P&P 28.5/25 valve head, Tilly 304, f275 cam, 1.3 rockers, and it hauls the mail...
Point is to get a good combo that works well together, in the power band you want, and tune it then go from there far as tweaking....
Depends what the head flows and the carb together also...
I have built motor with a mild port and polish, 27/24 valve head, 390 carb, 308 cam with Champ rockers fly!!!
I have also built a motor with a good port and polish, 32/28 valve head, 360 Tilly, 310 cam with 1.3/1.2 rockers and it flies...
Also built a motor with a decent P&P 28.5/25 valve head, Tilly 304, f275 cam, 1.3 rockers, and it hauls the mail...
Point is to get a good combo that works well together, in the power band you want, and tune it then go from there far as tweaking....