454 CI Mark IV cam Flat tappet VS> roller Question
 

Is the cost of going roller cam worth the power upgrades given a better cam profile availible with roller cams over flat tappets?

I am looking at rebuilding this winter, I have 454 .30 over with Merlin heads and stock 420 cams now with Holley single plane intakes, I know flat tappetwise I can go a little bigger and get 520 HP at least, my buddy did and dynoed his....

would going roller give me enough bang for the buck ? If I went rolelr I would do custom and then I also need tie bar lifters ... so I figure 800-1000 per engine over the flat tappets being 200 per engine..

I dont wanna spend 800.00 per engine to get 5 hp over what a flatt tappet would give me for 200.00 per engine..

Roller is deffinately the way to go now a days. It's overall a smoother operation. You have less power robbing friction and generally can have higher lifts yet keep shorter durations for a power band in the marine operating range. Increasing lift on a flat tappet requires more duration which raises the power band in rpms which you probably don't need or want. You would want to keep that engine under 5400 max rpm. No way will you see a 100hp increase by going with a bigger flat tappet.......or even with a roller. I'm sure a roller will yield more than a 5hp increase though. Cost wise weather it's worth it or not would be between you and your wallet. My opinion I would deffinately go roller. Don't forget you will need pushrods also which will be another $100+. Hope you got roller rockers too!!

Right, pushrods and valve springs, I have roller rockers already so thats good..

I will keep looking into this as winter appproaches...