I said I will start a thread on my own 454 to show how the right combination can easily make the number you want and I will take you through the steps and try to post as many pics along the way. Also I will dyno the motor and show you usable power, not in the 7000rpm range where most jets never see. I am a fairly new Dad so it will be slow so hang in there. First in my boat 1978 challenger is a pretty stock 454 Torquer II intake 750dp just had Jet perf. go through it and a DUI dist. Untouched dominator pump with lilricks gps ran 56.8 @4600rpm at parker. First I am just going to rebuild my 049's with some clean-up no porting and a cam change. This should put me well over the 525 mark. I will do my best to run this over to the dyno to back it up. Then as mone allows I will port the heads and step up the cam a little and be over 600 hp on Westech Dyno. I want you guys to know I am only trying to help others realize how important a combination really is. I am using Isky solid flat tappet cams, no roller. First cam is around 240/250@.050 and .600/.580 lift. (cam sheet not in front of me) my valve job is done and I believe this is were the biggest gains are. Now I use a 2.25 intake/1.94 exhaut valve. The valve area was opened up to unshroud the valves otherwise this valve size is pointless. Just a valve job from anywhere will NOT make the numbers. If you've ever heard of a mag called "Engine Masters" One of there top head guys is my buddy Brice. Hands down the work he does compared to a regular valve job is incredible. Not sure if I can post his shop& phone# on here. I am holding my flow charts from him and not sure if everyone knows there is a "good port" and a "bad port" on every head.                                                                                                           GM oval port#353049                                                                                                Good port stock intake @.550 254.8cfm Good port w/short turn clean-up @.550lift 301.8cfm Exhaust stock@.550lift171.1 Exhaust w/short turn cleanup and valve job@.550lift 219cfm I gotta run but I will post more in a day or 2. Later "D"
                                                           

 

I don't think pw_Tony was questioning the build but referring to the subject line "HP Ratings...Proof. 600hp 454 pump gas!"

I for one would like to see the results of a mild build with some good head work done.

  Your right! I started this because of another "HP" thread, so I thought I would try to help others with what I've had past experience building......but the title is mis-leading. Sorry about that. Anyways I didn't want to post old dyno sheets and their is some minor changes in cam profiles to build more usable power in a jet boat. Also just bought a DART oval port intake off "Racing junk" for $200 bucks brand new. It is a single plane 4150 carb style part #DRT-41214000 This manifold has a great mid-section for velocity and runner speed 1 of the best with some port work withOUT loosing bottom end! Most single planes seem flat. An area of big concern on intakes is called the short turn, intakes are cast by the 100's and really benifit from good port work, really widens your power. I will be shopping for a annual discharge 850 holley next! "D"

   Westech uses a Superflow 90290. You asked if it was a dynojet, I've only seen them in a wheel dyno? Do they even make a engine dyno? Not sure.The #'s will be corrected we will be in south OC so the correction with air den. moisture etc is ususlly less than 2-3% anyway. Gotta run talk to you guys tomarrow. "D"

If ya don't have 30 deg seats.. back cut the intakes. It helps low lift flow tremendisly!
Low lift flow is what starts it all when the valve opens.
Oh 25" or 28" of water? Just the basics is where most of gains are.

enough horse power talk,,,    who has the fastest boat already ? 

  Oh you asked about porting....I have 2 sets of BBC heads #353049 first set is to do a killer valve job increase valve size and blend the bowls, not a full port job. I will be going to a solid cam as well and try to run my beater motor to the dyno just to see whats cookin' . I am building another 454 with the same casting # full port job. solid cam, single carb deal that will make at least 600HP. Why 2 motors you ask? I don't want my river toy down for 1 and the #2 reason hmmmmoney! I have to do it over a couple of months and the small details in a quality engine really do make a difference as well. "D"

It's fine to post your bud's number. I have posted my good friend's number a few times here no problem, and he came in 3rd at Engine Masters Challenge twice  He's where I have gotten most of my "hp" knowledge from, or lack there of 

Also, I don't know if you can really call it a junkyard build or budget build if you're having a master porter port the heads, we all know how much money can lay into developed ported heads, how crucial the head porting is to the rest of the engine parts, and how the HP is really in the heads.... but I dunno I'm a crazy   

While you're down there, ask him about some facts on the heads, valve angles, sizes, back cuts, bowl percentage, etc..... so possibly the other back yard builders can come up with decently similar results 

  Sounds like you found a great pair of heads for yourself Mark! Maybe your old heads won't come close in performance....... but mine will. I also believe when I finish my pump gas, 454, solid flat tappet engine with dyno proven results it will decent set-up. Cyl head work is very crucial, there is some great ones and not so great as well. No disrespect but just selling you a pair of out of the box heads is much easier than what route I am taking. Good luck with yor summit heads....Whats the part # anyway? "D"

 Crap I'm tired, note all the type O's tonight...

   Sounds like you have a great combination! What hull is it in? I see your local, maybe see you in Parker....Thanks."D"