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Tue Aug 05, 2014 7:34 pm

I've read a few threads on getting properly matching heads. CC's, Step in and step out. How critical is it to match a stepped head to a un-stepped head in a stock application? General consensus seems to be it will run o.k from what I understand. What are the potential effects if any, Would it make regarding temps or other problems.

Tue Aug 05, 2014 8:35 pm

For one thing you want the ignition timing tuned right.
Tight deck, and higher CR tend to require less advance.
The opposite is the other way.

If one side of the engine wants 36 and the other wants 32 then.......well, it'll run anyway but it isn't very good

Tue Aug 05, 2014 10:49 pm

I am sure stock heads get mixed up and there are some vw's out there running a little weird due to mis matched heads. Probably no worse though than having the valves constantly out of adjustment or poorly tuned dual carbs or a worn out distributor.

Wed Aug 06, 2014 6:18 am

Got a motor that has a toasted exhaust valve and a nasty looking chunk missing where a plug helicoil was put in for a spark plug. Other head looks great. Think I'm gonna just get a new head and have the vendor machine the step out and cc it to the old one.

Wed Aug 06, 2014 7:33 am

Make sure the heads have the same size valves. CC the good head you have, so the vendor can match the new one to yours. When you get the new head, check the size of the ports to the head you have. Should work out fine.

Wed Aug 06, 2014 9:03 am

Thanks guys, I CC-ed head last night and sent the info for valves. Got everything I needed so problem solved. Thanks again.