I made a copy of the huge gibbs pencil popper it had great action but at close to five oz it was a bear to fling. Does anyone out there have a suggestion for a spinning blank that could throw 3oz to five? thanks chuck

Chuck,

I would try lightening up the big pencil first. A 5 oz surface plug will unlikely gain you much additional distance as its quite unwieldy to cast at that weight. Most of the distance pluggers I know rarely exceed 3.5 oz with a surface plug and many of them cast well over 300'. I fished next to Zeno this past spring and he was putting the 3.5 oz yo zuri surface cruiser about as far out into the canal as I've ever seen a surface plug go.
As for blanks that will do the job(3.5 oz or so), there are a few...ssu120mh, gsb 120M, xra 1205. Good luck.

If you really want to throw stuff that large, an SB1213M will do the job nicely.