deck heights i know off top of my head thinking quickly 302 -8.2 351w-9.5 (think some early 69-71 blocks) are 9.48 or close to 460- 10.3 lol sorry this was not needed i see previous post theres a chart for your info i didnt see
my old sbf had Afr 225 on a 393 351 stroker they worked well. afr make nice stuff , but the Trickflow twisted wedge is as good and plenty out there used IMO
The only casting fractures I have ever seen on aluminum alloy heads are on the rocker stud bosses, which typically arises from coil bind. In other words, a builder induced issue. I have run TFS, AFR and Dart heads at on time or another on both Chevrolets and Fords. What sets most heads apart from one another is the quality of the machine work and the hardware they use.
The engine im building is going to be a 347, I was thinking about going with the afr 205s, my rocker arms are comp cam 1.73 ratio, the cam I currently have is the f303 ford racing, with a complete forged rotating assembly, with flat top pistons with valve reliefs that are +4.3 I think. with that being said, would most of you agree to putting on afr 205s or 215s? ive been doing as much research that ive been able to, and the only time ive read about the heads cracking has been due to over tightening of the bolts. Keep in mind im building this engine so if I ever want to make more power the block and rotating assembly will already basically be set to handle it, and the block is probably going to be a dart iron eagle sportsman block with the 3, 4 bolt center mains.
I'd say 185's are a better choice. I've seen similar combinations run well with 185's.These heads flow so much More than most 180cc heads.
It just depends on what your ultimate goals are for the long run.. but unless you want to go with larger power adders or spin that thing to the moon?.. 205's would be the largest I'd go with on that size motor. The thing to remember is that heads.. more specifically, port sizes.. are much like camshafts in that they control where the power band is most effective. Go too big and you'll give up power in the lower ranges and affect AVERAGE power output. The general rule of thumb is to size the head right up to and only slightly beyond the intended airflow requirement of the combination and no more. It's very easy to get caught up on airflow numbers.. but average port velocity.. within the cams actual lift range.. is what makes a motor feel bigger on the street. An example would be that if the head keeps flowing to reach 340cfm @ .800 lift and your cam is only popping the valves open to .600?.. then you chose a head too large for the application. Ideally it(airflow numbers) should barely climb much past the point of your cams max lift point. A flat and only slightly rising plateau, so to speak. Power adders can deviate from that rule somewhat(especially really big hits of N2O and they have special oversized exhaust ports for that application too).. but just don;t get the Stroker McGurk syndrome or you'll end up needing to rev the snot out of the motor(347 inches is not huge) when it's off the bottle.. and with really short gears to make things work really well. Also.. the SHP block would be fine well up into the 700 horsepower range and the iron eagle would be best for VERY serious applications. Personally.. I'd forego the iron eagle and put that cash into the competition style head for bit more power within the intended rpm range you're after here because that's where the most dividends will be payed out to your right foot.
Yeah, I definately agree w/ 101,those 205s will be all you ever need on that 347.I`m going to run ported Roush 200s on my 351 eventually when I make it to the trk.But my eventual goal is to build a 430ish 351w,w/ a after market blk etc.But I think the hds I`ll end up using will be Brodix BF202s,they will flow 370cfm @ .600 lift.I can`t see needing any more hd than that,sure the CHI & Yates are a little better,but how do you justify the cost.I know a 82 Merc Capri w/ a 434w & those Brodix hds on it that will go 5.5 sec in the 1/8,N/A,pretty stout.
