time to buy the heads for my 408 and i was wondering what all you guys think. ive got a budget of about a thousand dollars fully assembled. its a 408 speed pro 10.5:1 pistons 270 degree and .480 lift crane cam carbed motor. ive been looking and there is so many different ones out there i could use some advise.

thoughts on these heads...??? http://cgi.ebay.com/ebaymotors/ws/eB...category=33617

on a side note anyone mind explaining the difference in runner sizes??

thanks, jay

 

For a grand you're right between a high priced cast iron head and a low priced aluminum head (aftermarket).

I have run the Trick Flow G2s on a 400 with very good results using a very similar cam to that. Their specs don't really do them justice. They make power in a big way. Much better than my favorite "cheapie" cast iron performance heads (Dart Iron Eagles).

If you can possibly spring for a few more bucks I would recommend a set of AFR 190cc heads. I bought my first set and all I can say is- they're worth the extra money. I had my doubts before, but no longer. They flat work. Like artwork that makes horsepower. Only additional parts I had to buy to use them was a set of 12-point head bolts. Couldn't get a 5/8" socket past the valve springs to tighten down stock type 6-point head bolts. The 190s are identical to the 195s except they are designed to fit a slightly smaller intake manifold port. The 195s are port-matched already to an Edlebrock Victor Jr. intake (so if you're using that particular intake the 195s are for you).

Intake cc's are a measure of how large the intake ports are. Bigger = more flow, but also less velocity. There's a balancing act between the two. Flow = HP. Velocity = torque (a major over-simplification, but roughly right). For a 400 with a mild cam like yours you probably want to be AROUND 200cc. Smaller is better as long as the flow is still just as good. Bigger with no improvement of flow is not a good trade-off.

And don't beleive manufacturer's flow data. They all lie.

Here's a link to Chevy High Performance's website where they flow tested a LOT of different cylinder heads against eachother using the same flow bench: http://www.chevyhiperformance.com/techarticles/41598/

 

you might look into a set of vortecs... thats what im using... fully assembled for 500$... youd want to have the better valvesrpinged ones they sell too... the ones in summit are like 700$ and have screw in studs and stuff i think... and take up to .525 lift or so...

if you are looking for good torque and arent planning on upgrading the cam later on, then vortecs would be a good choice because they have good mid lift flow and all... ill get some track times up and a dyno sheet when i get it broken in... (still waiting on headers)

 

I agree with that. I was admiring a set of the AFRs on the shelf some time back and the quality of finish is incredible.

I've heard good things about the Brodix Track 1 but have no idea what they're worth. I believe they are geared at the 400+ ci small blocks.

 

I would look for a set of AFR heads. I got mine used (1k miles, but in great shape) for $850 shipped to me. They are awesome heads and now I will use nothing but AFR's on any hi performance motor. Like said above, they just work and they flow like mad. An AFR headed 400 with a good sized cam will run mid-high 11's, and with the cam you picked would run low 12's.

 

kfoley where was it you found the afr's for that much? ebay?

i was also wondering what everyone though of the pro action heads

thanks jay

 

I got them from a guy on the classifieds section, but you can find them on ebay all the time, maybe not that low but you can find some good deals. The Pro Action heads are good too, but they don't compare to AFR's. For the Pro Actions I would look at the 200cc aluminum ones. You can get them pretty cheap if you look around.