For the V-8 engines made in the 70's, can anyone comment on:

1. Are the heads for a 450 SE or 450 SEL (117.983, 117.986) the same as the heads used for the 450 SL and 450 SLC (117.982, 117.985) of the same year?

2. Are the heads used on the earlier electronic fuel injection engines of that group, the same heads that were used on the later mechanical fuel injection motors?

Thanks.