Artanisman
Welcome to the inliners. First off I have never seen a dual plane intake for any ChevyL6. the offey & clifford intakes are a single plane. All the early Heads will fit your block.
Now as for a rebuild On any motor If your Not after the Max. It is always better to do a .030 over bore. This way you can always Do a rebuild again later on in life of the block. But if you after the add cubic inch,s for Power go with a .060 over and this still will leave some room for another build If need be.
The offey will give you the better low end to Mid ranger Power and tork. Going with a RV style cam or nothing more then a 500-550 lift hyd. cam. A cam with a lobe seperation Of 114,112,110 anything less will give a Much ruffer idle. And will move the power & tork band Higher up the Rpm scale. The Head is your biggest Issue to look at.
Do a nice port clean up a good 3-4 angle valve job.And for a Better add Boost in Head flow is do to a lump port. Even with staying with the stock size Valves. If your still looking to keep the MPGs it is all the better reason to stay with the stock valves. and top it off with dual exhaust.
Keeping all this in mind will work Very well for Both Motors. If you have any other Questions Just fire away. Hope this helps }[oooooo]
God doesn't like ugly.
