As Krazy mentions above, no one can tell you, there's too many variables. You have to get the parts and measure for yourself on your engine and take any steps necessary to get the needed clearance. Especially with aftermarket heads because they use bigger valves and move the valve centerlines around, the valve reliefs in your stock pistons often don't work. TFS twisted wedges are little more forgiving due to the valve angles.
It`s probably best to get the pistons to go w/ the twisted wedges,and as far as small cammed motors go,you would be surprised to see what they`ll do with a little nitros oxide.
Did you ever buy a set of heads Ive been doing more research as I never pulled the trigger first time around prior research brought up that the trick flow 170s would work with stock pistons(if no crazy duration/lift) and was more comparable to afr 185s Now AFR has come out with the Renegade(think 2012) versions since my last "research" and its being claimed that the New Renegade AFR 165s compare to the old design of AFR 185 Outlaw comp port heads..only 300 dollar difference
ah stupid me guess I didnt catch that this time around and didnt have good enough memory to tell me "thats not a pair dummy" lol
Trick Flow are actually cheaper than the AFR: http://www.summitracing.com/nv/parts/tfs-51410004-m61/overview/make/ford http://www.summitracing.com/nv/parts/afr-1388/overview/make/ford Micah
yeah 313.20 difference if it was regular AFR 165 design/port flow id say TFWH 170, with the new Renagade version AFR for sure
While I have nothing against any highly developed 20 degree head.. before pulling that trigger.. you might want to check out Trick Flows newest 11r cylinder head too. http://www.trickflow.com/search.asp?Ntt=11R&N=400098++115+368289&Ntk=KeywordSearch If those heads were being made in the high port design.. I'd drop my RHS project heads to get them in a heartbeat. I'd still chop into them too.. but would be starting with a better baseline, mainly due to superior valve angles and the better combustion chamber design.
Of course that question would be best answered by the mfgr themselves.. but I can only assume that due to the flatter valve angles involved(as with the original TW head design).. they should/could be more forgiving to the required notching that usually goes along with larger 2.02 intake valves. The original designs usually handle up to around .550 lifts @ about 225'ish duration until major clearancing issues start cropping up. The other thing to keep in mind is that the cam you'll likely be using to take better advantage of those AFR's may require some additional clearancing as well. Duration is far more of an issue for PTV problems than lift usually ever is. Just the nature of the beast when running bigger valves on top of a SBF, is all.
interesting question for ya guys. I happen to have a set of Mercruiser heads off a boat engine. I've heard that people put them on 302/351 but I want to know what they do fro you? Do they give a little more compression? power? id really like to know if theyd be a better option than my 68 302 heads. thanks
aside from using brass freeze plugs.. those heads are no different than any other smog heads of that era. Total junk IMO, and not worth the machining costs when you consider the much better designs available these days. GT40 heads are cheap and have considerably better chambers for imoproved burn characteristics and higher compression.
It depends on what the heads are. GT40's were used in a few marine applications. They have "GT" cast in the corner, next to the valve cover and three vertical bars cast in the ends. What year vintage is the boat engine ?
