Vortec Heads??

[KyHeadhunter1]

I have a late 80s or early 90s 350 in one of my boats. (Serial# B625423) The amount of hours on it are unknown, but the compression is fine and the motor purrs like a sewing machine. Somewhere in the loft of my barn I have a set of 1998 factory 350 vortec trucks heads that have right at 80k miles miles on them. Would I get any significant power out of putting these on my boat with maybe a performer style intake and maybe a 262 series cam? I am running through prop exhaust and I am probably going to keep it that way. I'm also running stock T4 ignition and the factory quadrajet. The boat is a 95 Baja 188 Islander ( 19' bow rider) that has a dry weight of 2800 lbs and its primary functions are tubing, wakeboarding, skiing and cruising. But on "boys day to play" a little more power would be fun. I have the parts laying around other than just buying the cam. Any suggestions?
Thanks for your time, Jim.

 

[wca_tim]

Re: Vortec Heads??

yes. dollar for dollar adding vortec heads, a mild cam (comp xm262 or similar), intake and carb, you get some nice gains throughout the rpm range. Have them cleaned up, fresh valve job, etc... and you're good to go... Marine spec split duration cam with longer exhaust duration is important and you shouldn't see much horsepower difference running through hull unless you get quite a bit more aggressive with engine mods. Apparently running the exhaust tube (instead of exhaust bellows) is worth a few horsepower and the tube is an awful lot easier to put on anyhow... Cheers

 

[KyHeadhunter1]

Re: Vortec Heads??

Apparently running the exhaust tube (instead of exhaust bellows) is worth a few horsepower and the tube is an awful lot easier to put on anyhow... Cheers

Exhaust tube? Where do I find those?

Are the factory valve springs adequate for this cam and will the pressed in studs be ok?

 

[TilliamWe]

Re: Vortec Heads??

The exhaust tube doesn't really make much difference on a small block, really. A big block it helps more. But the tube is easier to maintain, because it requires no maintanence!

 

[KyHeadhunter1]

Re: Vortec Heads??

The exhaust tube doesn't really make much difference on a small block, really. A big block it helps more. But the tube is easier to maintain, because it requires no maintanence!

I found the tubes on Summit Racing, however, the bellows that are on the boat now are in good shape. They are still soft and show no dry rot at this time. If there is not much of a performance gain I will wait till the bellows need to be serviced to add one.


I am not trying to squeeze every last bit of power out of the motor as the boat don't run bad now. We have stripped the interior out of it to freshen it up and that got me thinking that with the engine cover out of the way, it would be really easy to swap out the top half. It could easily be done start to finish in a weekend if I had all the parts together first.

 

[Fun Times]

Re: Vortec Heads??

So you know what you're working with, you're engine # 0B625423 is an 1987 Mercruiser 260 model # 02602347.

 

[KyHeadhunter1]

Re: Vortec Heads??

So you know what you're working with, you're engine # 0B625423 is an 1987 Mercruiser 260 model # 02602347.

Thank You!!!! I have tried to figure it out, but on the sticker on the valve cover there is no "O" in front of the B. I didn't know I needed to add it in. Thanks!!!

 

[greg82255]

Re: Vortec Heads??

I'm not sure it applies to a 262 series cam, but my vortec heads had to be machined for the extra valve lift with my 270 cam. May be something to look into just to be sure.

 

[KyHeadhunter1]

Re: Vortec Heads??

I'm not sure it applies to a 262 series cam, but my vortec heads had to be machined for the extra valve lift with my 270 cam. May be something to look into just to be sure.

Hi Greg, thanks for the reply. I read your post front to back last night (because I do have a complete 1976 Chevy 400 small block up in the loft) and I decided that was WAY more work than I have time for. That 400 will just wait till my boy has a use for it....LOL! It was reading your thread that made me decide not to try to replace my whole engine and that just replacing the top end will be more than enough. I have the knowledge but my time is extremely limited as because of my job I am only home on weekends. Thank you very much for posting such a detailed build thread!

Does Anyone know if I need to make any mods to the stock vortec truck heads to run the Comp Cams Extreme Marine 262 cam?