after reading my original post, it was pretty vague. Here is the total scoop. I have the complete MPI setup currently in operation on the engine described in my post. It has the damper pulley cps, V-belts, a/c and is the kit that HESCO sells. I intend to swap all the MPI parts to the 99 engine. It's basically a long block with all accessories missing. I'll use my 91-95 distributor and coil, etc from the 4.2L engine. The 99 engine still has the dist. in place. Is there anyting special I need to know before swapping the distributors out. I'll replace the waterpump with the correct one for v-belts. The biggest issue is the flexplate. I've been told to use the same model year flexplate as engine(99)and to bolt the 4.2 flexplate to the 99 4.0 flexplate and redrill the tc mounting holes to match the 84 model 999 tc. Since then I've been told by someone at HESCO to use the original 999 flexplate that it will bolt up to the 4.0 and I can use the OEM 4.2 starter instead of the very expensive late model starter. He also said my 4.2L damper pulley for the CPS would bolt to the 4.0 crank snout w/o any problems. If everything Hesco told me is correct then this will be a pretty simple conversion, if not, it still will be pretty simple just more expensive, If I've left any info out you need just let me know. I just need another opinion before starting. I'm also going to replace the rear main seal and oil pump before I start along w/ new freeze plugs. Thanks for your help.