How much hp can I add?

[Jpimley00]

So I want a better hole shot when there are lets just say a little bigger friends in the boat. My 351 commander says 260 on the valve cover. I was wondering if any one has added a few hp to the moter. Does the tranny hold up to 300 hp?  I have been looking into outing some gt40p heads from a 5.0 explorer to bump up compression a little and add what people say is around 40hp. If I do this in the winter this year I would also get an intake manifold that flows a little better, might as well if I am already taking it off. I don't care about over all top speed. It's fine how it is. If I get the weight in the right spot I can hit 40 which only burns fuel at an alarming rate.

I am looking to get out of the water alittle faster with one or two extra people in the boat. If every thinks the tranny can hold more power then I might think about doing it.

[backfoot100]

The tranny isn't an issue. I know of guys running 500+ HP and twist the propshaft off without putting a dent in the tranny. I'm running 400HP on my bone stock OEM tranny with 1400 hrs. on it. Never been rebuilt but has had the seals and gaskets replaced. As long as you change your fluid like your supposed to, it'll be fine.

If you want more holeshot, leave the engine alone and put an Acme 541 prop on it. You'll be amazed at the performance improvement. That by itself should probably be sufficient for your needs.

GT40P heads and a Stealth or Performer RPM intake will indeed give you another 40+HP. Probably the best bang for your buck performance increase you'll ever find. Don't mess with junk yard Explorer heads either. Call Tristate or Clearwater heads. Pick up a set completely worked over with new valves, guides and ready to install for about $600/pr. Just make sure that you tell them you want brass freeze plugs and to drill out the head bolt holes to accept 1/2" bolts. You're good to go.
That along with the 541 Acme is a really hot ticket.

My bigger concern is your WOT top speed. 40 sounds a little slow to me. What boat, how many hours and when was the last time a tune up was done on it?

[Jpimley00]

It's an 87 advance. 490 hours. I tuned it up this year cause it would fall on its face out of the hole. I think I put 67 or 68 mains with a 6.5 power valve. Pertronix, plugs and wires. It runs like a top now great hole shot with 3 people on the boat. As for the top speed I tested it last night cause I never tried to top it out. 40 is all I ever did. It went 48 last night by GPS with 4 people on the boat maybe 850lbs.

Thanks for the info I just like more power. I can't leave things stock for some reason and I love working on motors. I will look into the tristate and Clearwater heads.

I have been thinking of an acme 541 maybe I will start there.

[Midskier]

Stock 351 motor, stock sand cast 13x13 prop - 490 hrs, 87 advance, 48 mph on gps .................

541 is about the best of the best for hole shot and top speed - drop to the 543 for even snappier out of the hole
but may drop top speed @ least will spin another 200-300 higher - which would put your set up @ 5000-5100 rpm according to the info provided -
I'd run my digital tach and my dedicated GPS - (not a phone app) to get a baseline then go from there

Dan T

[Midskier]

is your commander blue or gold? aluminum (black) or stainless exhaust

[Jpimley00]

Commander is gold with black exhaust. Not the best photo but all I had on my phone from when I bought it this year.

My GPS was my hand held garmin 62 it could be plus or minus a mph or 2

Stock tach but rev to 4200-4300 rpm
I was going to bring my digital tach to see if it was close but I haven't cared much.

[Jpimley00]

This engine is more of a grey color

It does have the stock 13lh13 Michigan prop also.

If I am looking to ski off the boat more than anything is the 541the best  so I keep my top speed the same?  Any thing sounds better that the stock prop right?

[backfoot100]

If I am looking to ski off the boat more than anything is the 541the best  so I keep my top speed the same?

Yes. As Dan stated, you'll get a much better holeshot and on top end you'll stay the same or even get another MPH or two. The surface area of the Acme props are about the same surface area of a four blade for a much improved holeshot but still have the top end speed that a three blade provides.