Good head gaskets, good upgraded fuel system, and a good tune the stock 502mpi will run no problem. I say leave it on there if you take it off you will notice a big diff. in the power.

I've seen half assed jobs last forever and I've seen well thought out and installed 502's blow in a month. The A/F ratios need to be checked to be sure.....it's a crap shoot without check the A/F though...