sinning

Ok guys peep this ive been tryin to restore my friends and I 280z it does have a decent amount of rust and we where about to start replacing panel for panel........ when we strucked gold a man sold me and my friend a 78 280z with no engine but the shell all panels with no rust so now we will swap the engine and for the other datsun we are going to start fixing it piece by piece since we got something to drive in.... now the good question what engine should i put in the datsun.. oh yeah this datsun is going to be straight up performance with a roll cage i want this car for racing so its only going to be used once or twice a week any suggestions would b appreciated this project will take time since funds are not at my disposal i gotta go work hard for it thanks guys.......