Engine Help!!!

When I bought my boat (1987 American Skier with a PCM 351w), I rebuilt the motor and just threw the carb that came on it back on it because I didn't think I needed a new one. First trip out, I discovered that the carb (edelbrock 1406) needed rebuilt because fuel would pour out of the primary venturies. Everything was going ok until about a month ago where every once and a while when you floored the throttle the engine would die unless you backed off, but you could back off and go right back down and it would run. Then last week the lake was really rough and we were hitting some rollers pretty hard to get to a cove to board in. We tubed and boarded for a bit, and then shut the boat off to chill for a while. When I went to start it back up, it didn't want to start. It took a while, but I got it to run so we started idling across the cove to go pick up the tubes. After we got the tubes, the motor wouldn't wrap out and would start backfiring. I made it back across the lake and pulled into the cove our marina is in and it died. Popped of the flame arrestor and fuel was pouring out of the venturies just like it had before. I let it sit for a while and then a guy that knows quite a bit about engines said he'd take a look at it. He tapped on the sides of the carb to make sure nothing was stuck and she fired right up. He also said that him and a buddy of his had this same style of carb on their trucks at one point and had nothing but trouble with them. He suggested I put an inline filter between the fuel pump and inlet on the carb, and replace the carb. So my questions are: Has anyone had similar trouble, should I wait to replace the carb to see if it happens again, and what carb should I replace it with? The 1406 is a 650cfm, and by my calculations, which I don't know much, a 500cfm would be better.

Any help would be appreciated!