picked up some x heads today..are they worth swapping

[swinger340]

I don't believe you will see or feel much of a difference until up over 5000 rpm which you probably are not doing much of with that cam rear combo. I put a set of X heads on a bone stock 72 340 w the factory .444 cam and 3:23s. no noticeable difference. I ended up going w a higher compression 340 w bigger cam and lower gears and then I saw a difference. Its about the whole combo, not just bigger valves if you don't have cam and gear the bigger valves are useless

 

[moparlover]

In my opinion only. I would never dream of putting heads with forty five year old technology on my engine. I'd sell those X-Heads to someone that thought they needed X-Heads and sink the bucks into these.

bucky's car runs iron heads.
bucky's car has 45 year old technology.
8.5 seconds later bucky has gone 1/4 mile and you are 4 seconds behind him.
bucky wins.
bucky goes home with money.
you dont.

http://www.buckysltd.com/racing/

 

[gniknayrb18]

I don't believe you will see or feel much of a difference until up over 5000 rpm which you probably are not doing much of with that cam rear combo. I put a set of X heads on a bone stock 72 340 w the factory .444 cam and 3:23s. no noticeable difference. I ended up going w a higher compression 340 w bigger cam and lower gears and then I saw a difference. Its about the whole combo, not just bigger valves if you don't have cam and gear the bigger valves are useless

So what cam should I get and what gears...I don't mind spending the extra money making it right

 

[gniknayrb18]

bump