Drowning in decisions on a 454 I thought was smart to buy

[azhouseboater]

I'll admit I'm probably way over my head with this project but I picked up a nice 1984 Eliminator Sport Cruiser here in Phoenix that had the adapter plate on it for a Mercruiser drive. A Bravo 1 outdrive with 1.5 ratio, and a 1983 260 HP (350) Mercruiser with only 150 hours on it. But I talked to a mechanic with the similar boat and a few other people and they suggested since I had the Bravo drive and since everything was out of the boat that I should really just go ahead and drop in a 454.

So I picked up a rebuilt long block that was bored to 461 but now realizing I have a bunch of decisions to make that are above my knowledge so any suggestions would be great. I would probably be happy around the 400 420 HP that he said it would make. Not looking to get too crazy with it or spend too much more money on it.

I'm wondering things like.

1. Will I have to worry about reversion with the stock mercruiser exhaust on this setup with the Comp Cam especially since it's setup for thru hull exhaust below the swim platform?
   
   
2. If I do have to look at aftermarket exhaust any suggestions that won't completely break the bank?
   
   
3. Since I'm not sure I want to start borrowing parts from the 350 Mercruiser (might want to drop that in the houseboat I have) what about ignition? Seams like the MSD is expensive, DUI might not be too bad, or for the HP and RPM probably being under 500 just find a stock Thunderbolt?
   
   
4. Best carb for this setup since the one I got with it turns out to be an automotive one?
   
   
5. Since the heads have supposedly been redone just run with them or look for something better before dropping everything in the boat?
   
   
6. Say screw it all and drop in the stock 350 to start enjoying the mid 80's in Febuary they say are headed our way next week?
   

As for the build details here's what the seller said about it.

7.4 liter 454 bored 30 over to 461. Polished crank, high volume oil pump, clevite bearings, stock rods, forged flat top pistons, new rings, new valves, new seats, comp cams rv grind with springs, comp cams treated push rods, torker intake, rebuilt edelbrock 750 cfm carb, all new gaskets and seals, Never fired zero hours. This will easily power any boat or hot rod looking for 420+hp.

Believes they were Corvette High Flow Heads that were milled to match, around 9.5 to 1 Compression, and it should be around 420 HP with stock exhaust and 450 with a good aftermarket.

He was pretty positive that the cam was a 11-232-3 Comp Cams Extreme Marine with new pushrods but he wasn't sure on new lifters. He thought they might be solid lifters which doesn't make sense to me.



Here's what I have determined it has so far.



Block – Looks to be 1991 (Gen IV) Mercruiser 7.4 Model 47B110DS. Bored 30 over. 2 piece rear seal and he was pretty sure 2 bolt mains. Serial Number: D521426



Pistons - H426CP .030 02815-12A-A
Sealed Power Sealed Power Hypereutectic .100 Dome w/ 1 Relief
H426CP30
http://www.northernautoparts.com/part/sl-h426cp
Head CC / CR
100.0 / 9.84
106.9 / 9.37
109.4 / 9.19
116.9 / 8.69
119.0 / 8.56
124.0 / 8.27


Heads – 14092360 Peanut Ports I guess (so much for Corevette heads). Not sure how he is coming up with the 9.5”1 compression with these heads unless they really milled them down.


Cam – Assuming that he is correct in that it's the Comp Cams 11-232-3 Hydraulic Flat Tappet. 0.505/0.515 lift, 262/268 Duration, 218/224 Duration @ .050” Lift, 112 LSA
http://www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=403&sb=2



Exhaust – Stock Mercruiser Cast Iron 89011 with standard riser that looks like it should match up close to the S Tube setup they have going out thru the transom under the swim deck.



Carb - 750 CFM rebuilt Edelbrock 1411 (unfortunately automotive rather than marine version)



Intake - Dual Plane Intake – Looks to be HZ-PC23000 by web search or the SE Sport Dual Plane on the CP Performance Site
http://www.cpperformance.com/p-1354...chevy-oval-port-intake-manifold-polished.aspx
http://www.cfrperformance.com/CHEVY_BIG_BLOCK_DUAL_PLANE_INTAKE_MANIFOLD_p/hz-pc23000.htm

Thanks in advance for any advice you guys might be able to provide.

 

[hallett21]

You may wanna throw this in the lounge for more exposure


Sent from my iPhone using Tapatalk

 

[obnoxious001]

The cam is mild and should not have reversion issues being under [email protected]". You might look at one of the new Holley Marine Avengers, I talked to one of the Holley techs the other day about a pair of engines I built for a customer and he was pointing me that direction. They make a 770 cfm that might be good.

The biggest problem is you are not certain about what's in it, especially if the heads are not what they were stated to be.

 

[Blownbillybob]

I think I seen this boat on Craigslist

I would jus put it together for now get it running and see what u got!!
U can allways make changes later