Need a valve spring recommendation for a Gen V 454 that I'm installing a 454 magnum roller cam into. I'm using Howards retro roller lifters, 3/8 hardened pushrods, 1.7 Scorpion roller rockers... Planning on spinning this to 51-5200 rpm. I'm using the stock peanut port heads with ARP studs. I was told Comp Cams 911-16 springs would be perfect( although that's per summit racing tech, and I'm not sure if they are in tune with marine builds). Any input would be much appreciated so I can get this buttoned up before the end of summer. Thanks in advance!!

Anyone?

Specs of cam? Don't expect too much performance upgrade if your using peanut port heads . Large oval port work great for low rpm engines but the peanuts are a waste of time

Are you using the mag crank too??

Specs are: 224/224 duration 483/483 lift(1.7 RR's) with about a 115 LSA. Motor is a stock 330 bottom end with 200hrs. I realize peanut ports aren't the best but I'm willing to bet this motor makes at least around 375hp with the mods I have done. I wanted an increase while still keeping it reliable. Not putting a $7,000 motor into a $12,000 boat. Luckily I already had EMI thunder manifolds and just upgraded to SS 16 inch risers.

Thats a stock Magnum cam. Competition Products has new GM take out springs for that cam very cheap.

Ok thanks. Do you think a comp cams 218/224 510/510 on 112 would make that much more than said mag cam with free flowing exhaust, dual plane, 750 holley etc? I'm at the point where I need to make a decision. I know others have made 400hp fairly easy with this combo.

Guess the mag cams 115 LSA is maybe a bit conservative with such free flowing/ reversion resistant exhaust. Thx!

Borgie- With the cast internals, I'd stay with the mag roller and springs. I don't think you are really going to want to go much past 375 hp. I think the mag cam would actually work pretty good with your heads and the valvetrain at least will be very reliable.

Yeah I tend to agree. No need to get crazy with cast internals. Where would I find these springs you speak of? I might just stick with stamped rockers as well if reliability is going to be better. I probably don't need ARP studs and all with around 375hp. Thanks again for the advice.

You will be lucky to get 360hp with the peanut port heads even with bigger cam. My engine is a 468CI 330 bottom end (9.1 comp) with 188 heads, Isky 270/280 mega cam (bigger than Mag cam but not much), Isky lifters, one piece push rods, 1.7 Scorpion roller rockers, Edelbrock intake, Edelbrock carb, all ARP bolts and studs. I paid to have it broken in and tuned on a Dyno and it peaked 407HP at 5000RPM. And that is fine for me since I don't want to spin it over 5000RPM due to the cast lower end. Those peanut ports choke the engine, the main reason the mag makes 365HP is due to the bigger rectangle port heads not the bigger cam.