Pushrod length
For sure you will need the 3.91 gears and the convertor.If you intend never to go over 6000 rpm,and this motor can do it with ease if balanced and blueprinted right,the eddy heads would be over kill for it and a big expence,whem a stock head can give you the flow numbers and the runner cc,s you need to do the job at a lot cheaper price.What are the cam specs on that cam,al of them to run some tests on the set up,Mrmopartech