bryonbush 85 Report post Posted October 19, 2016 Got a chance to get Afr 185 #1422 for a good deal. It would replace my edelbrock performer rpm heads w/ the .202 valves on my 351w that's .30 over and sitting at 9.5 compression. It has a performer rpm intake as well now. Will this help or hurt by going to these heads? 1 WilliamFug reacted to this Quote Share this post Link to post Share on other sites
MikeStang 247 Report post Posted October 19, 2016 Byron I don't think you will see a huge difference to be honest. The performer RPM heads are a good head as is. unless your stepping up the cam I don't really see much a need to spend the extra cash to be honest... Don't get me wrong the AFR's are great heads and I am running them right now but for what little you will gain makes the dollar spent per Hp gained not real good. IMHO Quote Share this post Link to post Share on other sites
Vicfreg 773 Report post Posted October 20, 2016 I have the Performer RPMs and they are very high quality and perform as advertised. The AFR heads are very similar to the Edelbrock ones. When compared to the "large valve" Edelbrock heads, hey have the same intake valve diameter (2.02") and very close intake runner volume (185cc for the AFR, 190cc for the Edelbrock). I can't see how you would see any appreciable difference in the performance by swapping heads. Even if you have the Edelbrock heads with the 1.9" intake valves, the flow numbers are so close throughout the whole RPM range, that I really won't make a difference. I went with the smaller intake valves. Mostly to avoid any valve to piston clearance issues. Hope this helps. Quote Share this post Link to post Share on other sites
RPM 1,190 Report post Posted October 20, 2016 I went with the smaller intake valves. Mostly to avoid any valve to piston clearance issues. Hope this helps. I had to fly cut my 10.2 cr KB pistons with those #1422 heads. Quote Share this post Link to post Share on other sites
Vicfreg 773 Report post Posted October 20, 2016 Right. If you have a cam with a lot of valve overlap, and high lift, then you for sure need to check both the intake and exhaust valve clearances. I built a 393 stroker with KB pistons and couldn't get the clearances I needed with the bigger valves. When I looked at the flow numbers, I just used the smaller valve heads. I was too far along to machine the piston top eyebrows to accommodate the big valves. Are you happy with the quality and construction of the 1422 heads? May consider those for my next small block build. What kind of cam and rockers are you running? Quote Share this post Link to post Share on other sites
RPM 1,190 Report post Posted October 20, 2016 Haven't driven it enough to have an opinion other than the cnc'd ports are pretty darn cool. I do not like the stock narrow spaced exhaust mounting bolt holes. With the bigger exhaust ports and stock bolt hole location, it leaves not much room for the gasket to seal. If I was to order another set of the 185's I'd get the additional wider holes. Quote Share this post Link to post Share on other sites
MikeStang 247 Report post Posted October 20, 2016 I'm running the ARF 205 Nitrous ported heads on my 408. Running Ross pistons if I recall and didn't have to cut the eyebrows.. Cam is a nice Hyd roller with a 112LSA and about .600 lift...it runs like a beast and idles oh so easily with plenty Vac for power brakes.. Quote Share this post Link to post Share on other sites
bryonbush 85 Report post Posted October 21, 2016 right now i decided to hold off. Another guy on VMF was doing the exact swap and said that by the numbers, he expected 30-50 hp gains. my engine builder stated with my set up to see 40-60. but to make the best out of them, to switch to 1.7 rockers to avoid a cam change. with that it would get me 60-80. buy the time i purchased the heads, bought rockers, then had everything installed correctly, its a chuck of change. my ultimate goal is to either boost this motor or go right into a BA stroker build. Quote Share this post Link to post Share on other sites
MikeStang 247 Report post Posted October 25, 2016 Man I don't see a 40-60hp Gain over your Performer RPM heads Honestly. My good friend is running a 408 with Patriot Performance Alum heads and Hyd Roller that's almost same size as mine is, his cam is ground on a 110 LSA and lift is within 5 points of mine, and altho hes running a 5spd VS my 4R70W automatic, his car is damn near as fast as mine is from a 50 mph roll and we have same car, same gearing etc... we are as close of a match motor wise except for heads as you can get... He runs a 750 Holley on a Per RPM intake , I run an 850 Holley on a Vic Jr Intake and bottom ends are almost identical...BTW His car put 410hp to the wheels running Pig Ritch, My motor made 550 at the Flywheel... Sooo... Lets assume he is loosing 15% power through drive train loss...that means he is making around 471hp at the fly wheel...its probably actually closer to 20% honestly, plus he was running pig rich, so at 20% loss plus being way fat,his motor probably makes around 490-500hp at the crank.... Keep in mind your Performer RPM heads are Leaps and bounds better than his Patriot Performance heads are I'm sure of that.... So I can honestly say the AFR Heads are 40-60hp better than the Patriots, but don't think they are that much better than the Performer RPM's are in real life... I think if you did the AFR's and rockers etc... and dynode motor before and after you would see 40hp MAX increase...and for the cash you would have to shell out its not worth it... A better option would be to take the RPM's off and either have them CNC ported and worked or send them to Mayeaux racing heads here in Louisiana and let him work his magic...then I bet you would get the power you want. Quote Share this post Link to post Share on other sites
MikeStang 247 Report post Posted October 25, 2016 The smart money is to just get a little 50-125hp N2O kit and bolt it on. You got forged pistons and all the good stuff in the motor, so there is NO reason it wont handle a 125 shot Easily with no problems....And IMHO N20 is safer than Boost because you got less shit to worry about. Be sure you run a conservative tune and get a wet kit and hook it up and let her eat... I ran a Top Shot kit on my motor on the dyno when we built it...Motor made 550hp, and a 125 shot got me 659hp... That's only a 109hp gain from a 125 shot but it was running seriously Rich because I was a little scared of it at first on a brand new motor, but now..Pfff.. I leave it rich and hit the switch... Power on demand. 1 Shep69 reacted to this Quote Share this post Link to post Share on other sites
bryonbush 85 Report post Posted October 26, 2016 at this point im not going to do anything. I'm really leaning on going to an efi set up then going to a supercharger. Ideally i'd like to take my motor now and go into a stroker build with big heads. but then again, the efi is something that i can carry over to any motor. going efi ($1500) then the supercharger (2800) i think im still under the cost of what the 408 would cost to build. edit to add: i had to run a 2" filter for my combo to fit under the hood. How are you guys fitting the bigger heads/intakes in the bay? Quote Share this post Link to post Share on other sites
BuckeyeDemon 211 Report post Posted October 26, 2016 How are you guys fitting the bigger heads/intakes in the bay? drop base air cleaner. Quote Share this post Link to post Share on other sites
bryonbush 85 Report post Posted October 26, 2016 drop base air cleaner. I have one on there now. Is there a difference between the 302 and 351 motor mounts? I reused the ones off my 302 for my 351 swap. Quote Share this post Link to post Share on other sites
BuckeyeDemon 211 Report post Posted October 26, 2016 I have one on there now. Is there a difference between the 302 and 351 motor mounts? I reused the ones off my 302 for my 351 swap. just curious, how much drop are you using? i'm running 1/2" drop motor mounts, Victor Jr intake, shaker and have a 2.813" filter Quote Share this post Link to post Share on other sites
bryonbush 85 Report post Posted October 26, 2016 its a 1/2" drop base plate if i remember right. I'll have to look into the drop motor mounts but the only ones i noticed right away was the ron morris ones that are $200 something bucks which is a little steep Quote Share this post Link to post Share on other sites
BuckeyeDemon 211 Report post Posted October 26, 2016 its a 1/2" drop base plate if i remember right. I'll have to look into the drop motor mounts but the only ones i noticed right away was the ron morris ones that are $200 something bucks which is a little steep too many potential side effects if you were to change to the drop mounts. the intent of my post was simple a comparison and it seemed odd that i could be running a filter almost an inch taller when i have a taller manifold combined with the height restrictions from the shaker. Quote Share this post Link to post Share on other sites
MikeStang 247 Report post Posted October 26, 2016 I run a drop base air cleaner, and with the factory hood my air filter element was a 2" I think..When I swapped to Ridge runners GT500 hood it gave me a little more room so I went to a little taller air cleaner. They make a huge aluminum drop base air cleaner but its pricey...we installed one from the guys Sprint car that runs the dyno where I had my motor built and if I remember correctly it picked up like 3hp with just the base, then we put a 3" air cleaner and the top and it jumped to total 5-7 hp gain if I remember right. Quote Share this post Link to post Share on other sites
1969_Mach1 333 Report post Posted October 26, 2016 When using drop base air cleaner bases and shorter air filters don't forget the issue of air cleaner lid to top of carb and bowl vent clearance. Holley recommends 1", the other number number I've seen is 3/4". Part of it has to do with air pressure at the bowl vents and part of it to help the air make the turn to go down into the venturi's. For example, if you use a 1" or 1-1/4" drop base to lower the air cleaner, a 3" tall filter is needed to get the lid up high enough over the carb. The air cleaners MikeStang referred to are designed to help the air make the turn to get down into the venturi's. Also, there is the space between the air cleaner lid and base. It gets restrictive with a drop base and anything shrorter than a 3" tall filter. If you want an idea of the minimum air filter size needed based only on CFM requirements, K&N has some simple formulas on their website. Usually the stock size filter Ford installed at too small for the CFM requirements of a modified engine. Even in an K&N filter. That doesn't surprise me much. Setting up an air cleaner is MORE than just fitting it under the hood and can be a real chore on any Mustang with a 351W based motor or big block motor. I don't think the shorter motors, like 351C's, 289's or 302's have these air cleaner fitment issues. Quote Share this post Link to post Share on other sites
MikeStang 247 Report post Posted October 26, 2016 Agreed. I tried one of those filter style lids for a few months, when I pulled it off the carb I noticed all kinds of yellow fuel contamination around the inside top of the carb so I began to wonder if it was not doing more harm than good and was causing some disruption in the air flow, not to mention my RidgeRunner hood has a sort of Ram Air effect on the middle Nasa duct. Long story short, I swapped out the top and haven't had any problems with nasty fuel splatter on the top of carb.. I wish there was a way I could run a taller filter, but short of spending a few 100 on one of those fancy machined aluminum drop base cleaners I am stuck with what I got Quote Share this post Link to post Share on other sites
bryonbush 85 Report post Posted October 26, 2016 Mikestang, I've seen a lot of guys at shows having those top filters and always wondered if they worked. I want to get one but they get pricey ant not sure how much it will help. I'll have to measure how much space there is between the carb and the top, but I had to do something to get it to close Quote Share this post Link to post Share on other sites
