150 to 175 powerhead

[lastdrift]

help , can i bolt up a 150 omc 1986 cross flow powerhead 90degree v to a 1985 ,175 omc 90 degree v cross flow 25 inch long shaft that has a blown motor. Are the bolt patterns the same and the exhaust sections compatable also the splines for the flywheel any help is really app. thanx. jerry

 

[emdsapmgr]

Re: 150 to 175 powerhead

You should be able to swap them. The 86 150 is a flatback powerhead and the 85 175 is also. The exhaust adapters are the same. The ignition system on the 85 is the 35 amp alternator. (the 150 may also have that if it is the "S" model.) You can determine which ignition system you want to use-the 35 amp system is usually more desirable. You may want to reuse the 175 carbs, as they flow more fuel than those on a base 150. The 85 powerhead does have the intake filler blocks, part 322722 (NLA) which adds 5+ hp, so you may want to swap them to the 86 150 block. They are free hp.

 

[Faztbullet]

Re: 150 to 175 powerhead

The late model 1985 175 came 2 ways, flatback and bubble back exhaust. If the 175 has the bubble back you will need to change the exhaust adapter on the midsection to use the 150.

 

[lastdrift]

Re: 150 to 175 powerhead

thanks for the quick replys fellas i just got the model no. from the 150 head it is e150TLCUR iam asumming that is a 87 year block is it still ok for the swap thanks for all relplys and insight i will try and find out if the 175 is a bubble back exhaust thanx. jerry