Re powering 20 or 25 inch lower unit?

[wgammill]

My current motor runs fine although it is under powered for the boat. I can run 33-35 mph and have no problem getting on plane. With that being said it is a 1985 motor and if it goes out ,I'm wondering if a 25" lower unit would be acceptable. When I look at used motors here, craigslist, and eBay I see a lot of used 25" 150hp and some 20" for sale. The boat is a 1995 Javelin 387 with a 4" manual jack plate. I don"t know if a 25" would sit too low. What do you guys think? Is a 25 better then a 20? I will run the current motor as long as it last but I'm also looking in case something comes along. I don't need to run 60 mph or anything most of the lakes I fish are 500 acres or less, but there is one big lake here that I fish enough that a bigger motor would be nice.
Thanks,
William

[06 SB]

You will need the 20”.

[wgammill]

You will need the 20”.

Thanks that is what I thought but wanted to check