Head swap on 318?

[santaw72]

The cuda I am currently restoring has a 318 bored .30 over with a .500 lift cam and stock heads. i was thinking about putting 340 heads on it instead. im new to this and just looking for some feedback of what you guys think.  thanks, mike

[Chryco Psycho]

the best swap is to use the 308 casting 360 truck heads , they will make far more power then the early 340 heads do . We dynoed a simple head swap removing 340X heads & installing 308s on a mild 340 , we gained 41 RWHP on a mustang dyno . The 308 castings are found on 88-92 trucks , .
 The other swap is to use magnum heads from 93 up , they will bolt on But you need AMC lifter to oil up the pushrods , different pushrods , Chevy roller rockers , different intake  to make it work but the heads do flow well & make good power

[santaw72]

will the 360 heads just bolt right on? do you know whether those are the 2.02 valve or 1.88? and would i need to do something different to get higher compression seeming the combustion chamber is larger?

[burdar]

2.02 valves were gone after 71.  The 340's and 360's after that had 1.88's.  I've got 1.88's on my 360 I used to race and the car ran mid/high 12's.  2.02's aren't really nessesary on the street.

[Cooter]

Recommend 2.02 Intake and 1.60 exhaust valves, GOOD valve springs on the 308 heads as mentioned. Mild clean up in the bowl area with a port patch and that .500 lift cam should compliment nicely...

[Chryco Psycho]

you can mill the heads & use a steel shim head gasket to keep the compression or use the smaller 302 casting from the 318 of the same years , but the 318 casting has smaller intake ports , adding 202 valve helps the 308 heads as it allows the valve to be installed at stock height just like new .

[santaw72]

okay thanks guys!