repower advice

[evknot0127]

I have a 1970 20' sf with the transom raised to 25". Currently I have a 2003 yamaha f115 hung off the back of it with just over 300 hours. The motor runs perfect and is like a tank, only thing is that I would like to have some more power and top end speed. What would be some good repower options? I was thinking a e-tec 130...would putting a 150 on the back be to heavy? Does anyone have a 20' with a e-tec 130 on the back to give me some performance #s? I have two batteries underneath the very front of my console and a brand new stainless below deck tank under console too. Any info or advice is appreciated!