motor ?
 

I have a 88 scarab panter ...stock 454's w gill exhaust and 750 holleys...I dont know to much and i was told that my motors are 330hp...theres a sticker on one of the motors that say 365hp which i know was a option in that boat....question is if I do heads and intake manifold...re jet carbs and re prop...what will i gain out of the boat...had it up to 62 w 4 adults n full tank of fuel..rpm was around 5100....usually i run it around 4200 4300 n gps says 53mph...just wana gain some mph without really beating up the motors...

should not be to big a stretch to pull some HP out of the motors. You will need to identify the heads and determine if it was a 330 or 365. Drastically different internals with the low hp version having all cast stuff and small oval port heads. The 365's had all forged internals and larger rectangle port heads. The GILS and Holley are worth keeping. Its should be fairly easy to massage 450 hp out of those and i would guess you'd be in the 70 plus mph range no prob. The motors in my 88 Scarab are 365's and i think the sticker on the valve cover denotes that. Again you will need to positively identify which motor you have. If their 365's its and easy cam and intake swap to an easy 425-450hp, if there 330's it can get a bit more costly with getting rid of the cast stuff and small heads.

With the same heads different intake and no cam upgrade I would think you would only see a 100RPM increase maybe 1.5mph. It takes a lot of power to move these slugs....... I know :)