Iv read on here that you can put 416 305 heads on a 350, but it raises compression to 12:1 or higher.I read on a hot rod site that a longer duration cam would help but you'll loose low end power. I was planning on using these heads cause I have a set of 193 casting 350 LO5 heads that are swirl port for a tbi setup, they have grunt but loose power after 3500rpm. Would a upgraded ignition, longer cam duration like the comp cams thumper hydraulic 287 cam, ported heads, ported exhaust ports, and ported intake make it a decent street setup on 93octane pump gas? Thanks guys.

 

What pistons?

You only get that high of compression with flat top or domed pistons. Most factory 350's have dished pistons.

93 pump gas isn't enough for 12:1, although you probably won't end up with that much compression.

 

Well all I know is it was a rebuilt 350, I'd imagine everything is stock spec. So yea you're right, I haven't had the time to pull them off to see what's in there. Plus the motor only has about 10mi on it. Would those lifters be fine for the thumper cam?
Ok so in hinde sight what would be the CR be around with the 416 I have? There from a 57k 305 from advance auto.

 

With the typical dish/valve relief factory style pistons, the 58cc of 305 heads will give you 9.5-10:1 CR, depending upon deck height and head gasket thickness.

If they are the oft-used cheap rebuilder pistons with full dish, more like 8.5-9:1 at the most.

 

This is what they look like.
http://store.summitracing.com/largei...-423np30_w.jpg

 

Alright so its been awhile, I got the 416 heads apart and turns out they were already cut for 1.94in valves, now a full port job has to be done yet but while thats slowly being done I was looking into cams. I really like the comp cams thumpr series and was thinking more like the 287 duration cam. Any one else have a better cam to use? what about valve springs?

 

Comp XE series.

I don't know what possessed them to do that Thumpr series.

 

Ok I don't understand lol, are they not a good performing cam?
What would match up to fully ported 1.94in 416 heads with a rpm intake and holley 4150 650cfm carb?
The goal was around 350hp with a 2200 stall lockup and maybe 3:55gears.