got my 502mpi out of my fountain and doing some p/m work on the heads...springs,seals,retainers..etc.thinking about installing a set of roller rockers on the engine.how do you think will effect the engine and do you think it will be a waste of time.would this modifaction effect the ECM?THANKS

If you run hard yes it is worth it. If you cruise its a toss up. The ECM wont know they are there. You wont know either.

You will not see any performance increase with roller rockers. I would just leave the stock rockers.

Stock stamped rockers are a common breakage area. They also cause additional oil heating and they'll wear your valve stem tips. The problem increases significantly if you have a cam with alot of lift, heavier springs, etc. They're too cheap not to use- if you break a rocker you're at least done for the weekend. If the rocker causes ancillary damage, you could miss a nice sized chink of your season.

With the stock cam, there is no need to change to rollers.
How about going to 1.8 ratio roller rockers though???
Hmmm...

i put alumina roller rockers ran 2 years one broke lucky did no damge they were life time warrty i replace with crowler stainles steel 8 years on them no problens they say 20 hp on dnyo

We won't build or sell any marine motors without stainless or certain aluminum roller rockers. As said already here on this thread, they add about 10-15 HP on any big block (dyno proven), they keep the oil cooler, stabilize some valve train issues and are much more accurate in ratio than any stamped rocker.
Very good investment for the dollar. Just make sure you purchase quality units, like Comp, Crane, Crower, ETC.

Regards,
Ray @ Raylar

Simply put rollers have bearings and stockers do not. Bearings reduce friction and therefore add HP... The gains may not be tremendous but are worth the investment.

Keep in mind that if you're really fixed on staying with a stock stamped steel NON-roller rocker arm and go with a higher lift cam, you will need to make sure you have what is usually refered to as a "long slot" rocker arm that accomodates for the higher lift of the cam....not sure what the lift limitations are that the stamped rockers could handle. That being said, you should just install some well made roller rocker arms and be done with it.

If you don't want to pull out your cam you can go with the 1.8 roller rockers and gain about 300 rpms. I have used them in several stock set ups and have never had a failure. Every application saw an increase in RPM.