Does a 1999 Mercruiser 350 efi engine come with Vortec heads, if not would you recommend upgrading to them? Will these fit my engine? I have no compression in my number 5 cylinder and they are telling me i need a valve job. My engine has 185 compression in all cylinders except the number 5 cylinder that has 0. What can you recommend. i was quoted $1500 for the valve job and installation. Is this something I can do myself? What heads should i buy
Thanks

Thanks