454 mag build up
 

Have a friend with carbed 1990 454 magnums. Does anybody have a combination to increase hp by 50 to 100.

Would like to know cam, carb, rocker arms, valves, springs,intake and what if any head work was done to the stock heads.

Thanks in advance

Do a search on 454 mags. There has been a lot posted about them
From what I have been told you can get your 50 to 100 hp with a cam chnage, Keeping your intakes ( they are pretty good) If you aren't looking to go over the stock rpms you don't have to change carbs. Mill the heads .020, .030 if you have a little head porting done.
Now you are right at the level where an aftermarket exhaust would help.

The generally accepted method for increasing power on the 454 Magnum is to replace the stock rectangle port heads with Merlin oval port heads and install an Edelbrock oval port dual plane intake manifold. An aftermarket camshaft with 224/232 intake/exhaust duration on a 112 degree LSA and aftermarket high performance aluminum exhaust manifolds (Gil, Imco, Eddie Marine etc.. ). Use the stock carburetor and ignition system. Time the engines for 34 degrees total advance at 3,600 rpm and install extended tip/projected nose spark plugs (AC R43TS or Champion RV15YC4).
Dennis Moore

You would make aproximately 405-415 horsepower at 5,000 rpm and low speed torque/fuel economy would increase considerably.
Dennis Moore

Thanks, I'll pass the info on

If I was starting from scratch the oval ports would be a good choice. but, changeing heads/manifolds for 20 extra hp and maybe 20 extra lb feet of torque in the mid range seems not to be a good deal economically, especially since those 20 extra hp at 5000 rpm are from the CAM change to 224/232 and exhaust, you just wouldn't see much difference on the water with 20hp on top end and 20 lb ft of torque midrange. I would just go with the cam and exhaust unless you have a set of oval heads laying around.

I believe 405-415 HP is more than a 20hp improvement on a 1990 454 Mag.

Hi i just finish my engine with the combination you said and i was very surprise of the result.The test on the dyno gave 552 lb of torque at 4000 rpm and 440 hp at 4700 rpm. It's a 454 mag .060 over with oval port head of a 330 with a Comp cam 226/234,111 of lobe separation ,stock carb and ignition.So thank you