I took my boat out an something let loose inside taking out 2 pistons. Here's my question i have a 1985 mercruiser 260 i was looking at building a 355 Chevy using my block an adding a set of vortec heads. I'm not sure on what cam to use for my boat. Also what intake is best all I find is edelbrock 2116 low rise.

I wanna use my Qjet so I need a spread bore intake

If you are going to be that deep into a rebuild get a stroker kit. You will not be disappointed with the extra cubes and accompanying torque.

Vortec are fine but require some machine work with higher lift cams. Look at AFR, RHS, Dart etc. Lots of cam choices. RM Builder is one source, Comp and Crower have some nice choices. I would recommend going hyd roller.

I'm more into EFI stuff, but I think the AirGap manifold performs well. I'm sure others will chime in with more useful information.

it really depends on what your boat is? i uase the xtreme marine 268 and the 270..both great cams..

what year is your block? salt or fresh water use? if a flat-tappet 20 year old salt water use block, it is scrap metal. buy a roller cam block that had antifreeze in it it's whole life.

Marine Kinetics, aka Rmbuilder on here, he'll answer your questions.

I read the other day in hot rod mag or something along those lines, you can run the comp cams or GM beehive springs on vortec heads and run a "high lift cam", With no machine work. Not sure how high, but for those on a budget it might be worth looking into.

Just curious, but what let go in the motor?

You can run the beehive springs and run a bit more cam with the Vortex heads but they don't flow over .480 so unless you spring for porting there is not much to gain. I agree with "Trash." Go 383 with the stock Vortex heads and a mild cam and you will have 325 prop h.p.
If you want more h.p. you will have to go with a wilder combo. The low-rise intake kills the torque on SBs.

Those vortecs are the way to go, now there machined for highlift cams. It's fn too bad there garbage on bigblocks