I have two sets of heads, 416's and 193's. The 357 (350 bored 40 over), is a 010 block, and ran strong before I bought it and then took the top off of it (heads and intake) I’m just going off of what I got laying around….I don’t intend on porting or polishing…I’ll just use them as they are. The 416's fine on the 305. I just wanted to see what works and what doesn’t but I wanted to get opinions first. The 193’s worked fine on the 357 engine…..I heard that 416’s would boost compression and create more top end power maybe with a better cam….i’m also thinking about using an edelbrock carb vs my qjet. How high of a compression ratio do you think I would be at? Just wondering……thanks for the feedback

 

Compression is going to depend on what pistons it has.

The Quadrajet is a better carb than the Edelbrock.

 

It has regular pistons. I think they are flat tops with valve reliefs cut in them. I made a mistake and put stock 350 head gaskets on it so I have to change them to 40 over gaskets...D'oh!! But it ran pretty well on start up outside of the car. Now with 193 heads on, what do you think my cam tolerance would be? I want it streetable but want that aggressive sound.......I'm intending on just buying a 350 from the junk yard and let that be a test platform for the 416 heads. It'll be a lot cheaper that way. I'm still learning so I don't want to waste money if I can help it.

 

Since the factory used many different pistons over the years, and 0.040"-over means they aren't factory pistons (most likely), "regular" doesn't really mean much.

Pistons with valve reliefs could be anywhere from 4cc to 12cc, so, still inadequate information (the difference between the chambers of the two heads is only 6cc).

193 heads are "swirl port" heads. Fine for low-RPMs, not much for performance. Porting doesn't help. Over .450" valve lift, flow doesn't improve.

416's, on the other hand, had the best non-Vortec ports the factory made. They have small 1.84/1.50" valves, so 1.94/1.50" or 1.94/1.60" valves help a lot. So does "pocket porting" (aka "bowl work") to clean up the area just under the valves. Then they can flow to support much higher lift cams.

But, if what you really want is "the sound", keep the 193's and put in a Thumpr cam. Won't run any better, but it'll sound "muscle car".

 

Ok....pocket porting? I not sure about that that........I'm not that experienced yet. Anyway, the pistons are flat tops.....I am pondering several things. What would be a good cam to use for street with a good sound to it? What should I look for?.......advertised duration? I think 220 should be ok but would I have to change valve springs?

 

At some time, none of us were.

Here's how I learned: http://www.pirate4x4.com/tech/billav...0Abrasives.pdf

Starting at page 13 is the "bowl work". They go into short side radius as well (don't let the terminology throw you, the instructions explain it all very well),
but that's where the biggest gains come.

If you stick with the 193's, though, I wouldn't bother with any of that.

Is your block flat or roller lifters?

If you stick with the 193 heads, they have really good exhaust flow, so you can get away with a single pattern cam like the Comp High Energy series. This one http://www.summitracing.com/parts/CCA-12-210-2/ would be a good kick in the pants without exceeding the lift/flow capability of the heads or sacrificing too much on the low end (the Thumpr cams do both). If roller lifter, they tend to have lift greater than .450", so you're kind of wasting the lift.

If you go with the 416 heads modified as suggested, you'd probably be happy with a XE268H (flat tappet) or XR270HR (roller lifter).

Assume with any aftermarket cam that you WILL have to replace the valve springs.