New Member, I am about to acquire an 86 IROC 305/700R4 and want to install a 350 L98 or ZZ4 crate engine. I do not know if it is worth installing the ZZ4 if I want to retain the TPI? I believe I have read that the L98 350 block is a direct replacement and I will be able to use all the existing hardware with a new 350 prom, knock sensor, and injector upgrade. I am looking for a 300 to 350 HP engine. I am also considering installing an upgraded TPI system from a place in Wisconsin. Will I have to upgrade the internals in the 700R4 trans to handle 300 to 350 HP? I have read many of the engine swap threads, and frankly, I am confused by so many answers and many of them are several years old. Help needed, I want to use my money wisely. Thank you in advance for your help.