indy lax heads for mild 318

[peelo57]

I have mild build 318 on my Duster.

KB pistons for compression, about 9.4
lunati voodoo cam, 256/262, lift .454/.475
performer intake, 600 cfm vacuum secondary carb.
And headders and 2 1/2 dual exhaust.
904 trans and 2500 stall.

Basically now i have stock 318 heads, stock valve size.

Would these heads make sense on this engine.
shift points are about 5400rpm.
rpm area where engine keeps most of time is 2500-4000. so I am mostly inrested getting hp increase on this area.

Putting bigger valves on my stock heads or buying used 360 heads and building them would cost almost same as these heads, I live in Finland and machining is expensive here.

 

[273]

They make sense if you want more hp.
318 heads were designed for the 273 which give a good cfm per cid ratio for that engine.
340 has about the same cfm per cid ratio that's why those engine can rev cause they can breath. 318 and 360 got short changed in the head department.

The Indy heads will flow more than fully ported 2.02 318 heads and especially just valves and a little bowl work.

With the Indy heads you'll pick up about 75 cfm. Even with your mild cam you should at least pick up 1 hp per cfm 75 hp. And I'll bet very little impact down low. It's better to build up with head flow than cam for a streetable engine. That's why LS and Hemi have such high flow cylinder heads.

There's a guy on here with a 340 with stock cam and edlebrock heads that dyno 400hp which will be way more streetable than large cam stock headed 400hp 340.

 

[peelo57]

Good to hear. That sounds really good. Looks like i have next waste some more money

 

[jos51700]

seems to me that Magnum heads will waste a lot less, probably similar net on a small bore