Under the assumption that I'll need to freshen the top end at some point in the future, I've been watching unmolested head sets on eBay to get a sense of what they go for. Seems that $320 - $350 is the range for 'good' heads without broken fins and not needing thread or other repairs.

My thinking is that I would pick up a set and send them out to be freshened, to have on the shelf when the day comes to replace the existing heads.

On a stock 74 cube shovel, is there a noticeable benefit to porting work on stock heads? Or is that throwing money down the drain?

Will a stock 74 cube shovel run noticeably better with a set of S&S heads? Or would a different cam be necessary?

The bike is a daily driver so a consistent power band and dependability is high value, but I figure that if I'm going to take the time to pull anything apart, I may as well make improvements.

 

Unless you have extra money to throw around , I wouldn't bother. Those heads breath quite well as they are. The only thing I would do is a good valve job and have them machined for valve seals.... You can get reasonable power out of the stock heads.... I'm currently running stock heads with an S$S carb, Andrews #2 cam and 9:1 pistons... motor is at 72/68 with drag pipes and runs smooth and reliable...

 

nothing on flea bay is worn out if you read the add - having said that I would just re do what you have when the time comes - kibblewhite sells everything you need black coated valves, cast iron guides, seals, spring sets ect - almost every supplier has them in stock -

manley is more money maybe 75 / 100 bucks as a kit just because its manley

goodson sells hi quality HD replacements we buy lots from them over the years, they are a real machine shop supplier of the top shelf in stuff - pricy but the best

 

S&S heads are a great value if your stock heads are in poor condition or are in need of significant repair. The casting is much thicker and they do flow a bit better.

 

can I put valve seals on a stock 1976, or do the heads need to be machined to accept the seals?

 

depends on the valve guides you have and until you disassemble the heads its a moot question