Holley SysteMax II Kit Questions October 07, 2005, 02:04:34 PM I was looking at the Holley kit named above and the cam it comes with has a .509 lift on intake and exhaust. I was under the impression that my 86 motor cant have a cam larger than .500 without cutting valve reliefs. But according to their catalog, the kit is good for 86-93 Mustangs. The 86 Mustang had flat-top pistons too right? What do you guys think? Any experience with this? Quote Selected
Re: Holley SysteMax II Kit Questions Reply #1 – October 07, 2005, 03:00:40 PM I thought the 86 had flat tops too. Trying to dredge info from brain, but I though 87-93 were the reliefed valves. But 86 to 89 had the forged rods. I could be all wrong though someone else can prolly correct me if i am. been a day and my brian is all mushy.(stupid cold) Quote Selected
Re: Holley SysteMax II Kit Questions Reply #2 – October 07, 2005, 03:03:52 PM The Ford Racing book I have on Mustangs talks about the SO motors a bit and said the HO and SO motors in 86 were true flat tops. Quote Selected
Re: Holley SysteMax II Kit Questions Reply #3 – October 07, 2005, 04:40:25 PM Thats too much cam/valve size on flattops... If you want to keep the orig pistons look into the Trick Flow setup. Those heads will work with that much cam and flattops, I know I'm running such a combo... Quote Selected
Re: Holley SysteMax II Kit Questions Reply #4 – October 07, 2005, 11:57:25 PM if the kit comes with the heads,maybe they are the reason the cam will fit.possibly longer distance between closed valve and piston at tdc.but then again,maybe there is a side note in the kit that states that the flattop pistons must be notched first. Quote Selected
Re: Holley SysteMax II Kit Questions Reply #5 – October 08, 2005, 11:15:44 AM quote from mustang performance handbook...Quote1986 5.0 H.O.- "a thicker deck and semi-siamesed cylinders make this block considerably stronger than the previous 5.0 engines. compression was increased to 9.2 by eliminating the dish and valve eyebrows in the pistons."Quote"begining in 1987 ford switched to the truck head (E7TE casting) with its larger ports and 1.74/1.46 valves, 9.0 compression forged pistons (with .030" dish and valve eyebrows), a larger runner intake and the now standard 60mm throttle body." Quote Selected
Re: Holley SysteMax II Kit Questions Reply #6 – October 08, 2005, 12:14:18 PM I repeat... the ONLY aftermarket heads that will clear the flattops are the Trick Flows. That is because the valves are slightly rotated, and deeper in the chamber than the E7TEs or any other aftermarket head. Even the TFs have issues with really large cams... Quote Selected
Holley SysteMax II Kit Questions Reply #7 – October 09, 2005, 10:34:45 PM In addition to that stay away from the Holley heads....those things are garbage, as I have access to two articles (somewhere), and also three Mustang forum members showing me damage, where the rocker geometry is horrible on those heads...the valve guides might last 10,000 miles on new Holley heads before puking oil. Get some TF or AFR 165 heads, a Edelbrock Performer RPM II, and a TFS stage I cam, if you are wanting something that works excellent, and will actually last longer than a couple of oil changes. Quote Selected
Holley SysteMax II Kit Questions Reply #8 – October 09, 2005, 10:54:22 PM As TurboCoupe50 has already mentioned, there is only ONE aftermarket head that will fit the '86 5.0 with it's flat top pistons and that's Trick Flow Twisted Wedge....nothing else works without notching because everything else maintains stock valve locations. Quote Selected
Holley SysteMax II Kit Questions Reply #9 – October 10, 2005, 12:20:51 PM Hey Hawk I was just wondering if that TC in your post is same blue TC i use to see at summit ford a few years back at there show and shine? Quote Selected
Holley SysteMax II Kit Questions Reply #10 – October 10, 2005, 03:09:15 PM Yep....I've been going to the Summit Ford show for the past 11 years. Quote Selected
Holley SysteMax II Kit Questions Reply #11 – October 11, 2005, 11:19:41 PM I use to have Gray 87 T bird and Pearl Black 83 Cougar Quote Selected
1988 Thunderbird Sport, Former 4.6 DOHC T56 conversion project. 
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