scarab79

Hello Scarab Brothers & Sisters, I am new to this but have read alot of useful info. I am ready to install new 383s in my 79 300 what size props should I start with ? And trim tabs ? 9x30 or 12 x24 Drives are Bravo 1

humpster

how much horsepower do you think you have

scarab79

they have 325 hp at the prop they are the mercs. 6.2 whjch are bored larger and longer stroke

Rookie

iTrader: (4)

I would say 21" if you had BBC's, I'd start with 19" 3 blades. What was your torque?

scarab79

390 pounds

humpster

ya i agree i think 21s would work

Rookie

iTrader: (4)

My friends '89 Bravo Panther with 330's will spin a 23" mirage 4600. I assume you need more RPM's ~5500? with the small blocks to make your power. I would start with 19"

humpster

rpm at 5500 might be a little high my 350 mpi's
say they like the rpm around 4900 to 5000max on a stock motor but i guess that depends what you did with your motors

scarab79

OK Thanks I read in the 383s specs. that it was sea trialed in a 86 sea ray pachanga, did not give size or weight w/ the 383, bravo one drive and a 24 pitch prop. the boat hit a top speed of 63 mph at 5000 rpm that was a 20% performance improvement over the orig. set up that was a 350 Magnum, Alpha one Drive with a 21 pitch prop. and between 30 and 40 mph the 383 sipped 3.5/3.7 gallons per hour. I like that, but I know that I am prob. heavier and have twin screws. Also can you tell me now to put pics. in the Thread.

Rookie

iTrader: (4)

The only way you can post pics if you are not a paying member is host them with a site like www.photobucket.com