I'm getting a 29 Outlaw in about a week. It has the 502's in it and I wanna get a little more kick out of the engines. Has anybody tried different manifods such as IMCO or Gil and if so what kind of gains have you noticed? I wanna do the manifold's and the RPM kits (MSD, air filter & computer). I would like to know any results if someone has tried this before. Speed, RPM & prop.

Thanks
John.

John, I have a buddy with an Outlaw with 454's . He changed exhaust to Stainless Marines with a programed computer and didn't really see any significant gains. But you are in the right direction with changing the parts you've listed. Wardey

Baja John, I use Stainless Marine manifolds on a 502efi. Ran 70.2 stock and 72 with manifolds and no other changes. Good luck!

im looking to add manifolds to my 490 hp 502 as well. I m looking at Gils. My cam isnt to wild and Im having no probs with reversion with my stk manifolds. I was hoping for more than 1.8 mph tho. Maybe seeing my motor is modded I will see more gain. I hope so.

Put Stainless Marine Manifolds with the Stainless Steel risers on my 502 along with roller rockers and a K&N Filter. Don't know exactly how much speed I picked up but I can tell you this. I run neck and neck with the same boat with a 496HO. The 496HO's are conservatively rated at 425hp vs. my stock 415. I swing a 24 pitck labbed B1 and keep up with them with there 3 blades. My 3 blade is a little faster but it runs into the rev limiter. Bottom line is I am guessing I got about 2-3 mph and it is worth the $$$$$. Besides they look much better that the stock manifolds. Keep the stockers and sell them. I got 300.00 from the first guys I talked to about them.

CMI HEADERS

Definately Headers, CMI, or for less money but as effective, Lightning, Less weight, and in many cases, more RPM. Midnight

And much easier to change spark plugs!

STAY AWAY from Lightning !!! I wasted (2) 572 motors with their ceramic coated headers. Don't skimp on your exhaust, I tried to save a couple of grand and look what it cost me. The Lightning's inner tube rots out and before you know it you are hydro locked. I don't know how their new stainless ones are tho. But I use CMI's. Dave Warden

I've got a set of gil's on my 454mag mpi.Bought them from cp performance and they swear by them saying they are the best.I may have gained 1-1.5mph on top.I think the mid is a touch better.I still not sure if it was worth the two grand,especially running a stock motor. .02 cents

I have had great luck with EMI Thunder, IMCO Thumper, and the standard IMCO exhaust system.

The EMI Thunder and IMCO Thumper are priced about the same, with the standard IMCO system that includes stainless steel risers coming in a bit higher price wise.

We have had great results by adding a good flame arrestor, EMI or IMCO exhaust systems, and reprogramming the ECU. In most cases we have seen a 3 to 5mph increase.

My .02cents,
Don Baca
Triad Performance Marine