That looks like similar the Barbron(sp?) I have on mine and it flows well. I did back-to-back runs with and without the flame arrestor and saw no difference in speed.
That looks like similar the Barbron(sp?) I have on mine and it flows well. I did back-to-back runs with and without the flame arrestor and saw no difference in speed.
If you want to wake it up put some exhaust on it. That looks like stock 4". It was original on 370's. 420's came with a bigger exhaust. That is the most notable restriction in your package.
If you want to wake it up put some exhaust on it. That looks like stock 4". It was original on 370's. 420's came with a bigger exhaust. That is the most notable restriction in your package.
If you want to wake it up put some exhaust on it. That looks like stock 4". It was original on 370's. 420's came with a bigger exhaust. That is the most notable restriction in your package.
What he said. The 420's should have came with GIL manifolds. Those heavy cast iron stock merc ones you have do nothing for Horsepower. They use a common plenum, so the exhaust basically dumps into a big open chamber. Gil, stainless marine, and of course headers, have individual runners for each cylinder.
As for the Flame arrestor, what you have is fine for your engine. Just keep it clean. I clean mine with brake clean which works good. Of course take it off first before spraying it.
I see your engine has a Wieand X-celerator intake on it. That's original equipment. If it has Crane gold rockers it's definately a 420. Someone changed the exhaust from the original.
I see your engine has a Wieand X-celerator intake on it. That's original equipment. If it has Crane gold rockers it's definately a 420. Someone changed the exhaust from the original.