150 v6 interchange?

[taprooter]

Hi,

We have a blown 89 model V6 150 johnson powerhead ( rod went threw side of block ) and was wondering if anyone knows which years other 150 johnson powerheads will interchange with a 89 model? I've found a 78 model 150 and someone told me that it would not interchange as far as bolting to the lower section.

Will a 89 model powerhead only bolt to a 89 model or will other year models bolt up?

Thanks!

 

[emdsapmgr]

Re: 150 v6 interchange?

The powerhead base gasket is the same part number between the two engines, so the bolt pattern should be the same and it should bolt up. However, there were changes made to the shift rod and it's pivot on the block-likely that the old 78 powerhead may not adapt to the newer shift rod configuration. I believe the newer style shift rod started the next year (in 1979), so the 79 and up may fit. There are some other issues, like the choke differences, rectifier/regulator and VRO setup which you will have to deal with. Also, the older blocks do not have the boss mounts for the power trim box on the exhaust cover-also may not have the mount for your newer style power pack. Some other experts on the board may have the exact answer on the newer drive shaft splines matching up with the older crank, as well as additional issues.

 

[taprooter]

Re: 150 v6 interchange?

Thanks for the help!

So what you're saying is it will bolt up, it's just that we will have to make some modifications to the shift linkage, etc. in order for it to work if the drive shaft splines match the older crank?

We just bought the 78 model thinking that it will work without asking someone first, so if anyone here has a good used 89 model 150 johnson powerhead ( or one that will work ) that they like to do some trading for this 78 model... I'm open for some options. We bought the 78 model off ebay and they say that it has been rebuilt and has good compression. We haven't received the powerhead yet as we just bought it yesterday and should be getting it sometime this week.

I really appreciate the advice or any options that anybody has to offer. Thanks!

Dave