I thought you guys could help me i was wondering if gt 40s (cast iron ones) will bolt up to my 86 EFI
i think they should but want to make sure and if they do bolt up will they work with my speed density, and if it will run alright with the heads will the SD keep them from making a noticible difference worth the work to put them on
thanks for the help please lend me your expertise
by the way, will shorties make a difference (I know long tubes do but I already upgraded my exhaust)
P.S. if i do this i will also put in Comp cam:
<TABLE cellSpacing=0 cellPadding=2 align=left bgColor=#ffffff border=0><TBODY><TR><TD vAlign=top noWrap>Part Number</TD><TD vAlign=top noWrap colSpan=2>31-255-5 </TD></TR><TR bgColor=#dddddd><TD vAlign=top noWrap>Engine</TD><TD vAlign=top noWrap colSpan=2>1963-1995 Ford
289ci-302ci
8cyl. </TD></TR><TR><TD vAlign=top noWrap>Grind Number </TD><TD vAlign=top noWrap colSpan=2>FS XE250H-14 </TD></TR><TR><TD vAlign=top noWrap>Description</TD><TD vAlign=top noWrap colSpan=2></TD></TR><TR><TD vAlign=top noWrap colSpan=3><HR noShade></TD></TR><TR><TD vAlign=top noWrap></TD><TD vAlign=top noWrap>Intake</TD><TD vAlign=top noWrap>Exhaust</TD></TR><TR><TD vAlign=top noWrap>Valve Adjustment</TD><TD vAlign=top noWrap>0 </TD><TD vAlign=top noWrap>0 </TD></TR><TR><TD vAlign=top noWrap>Gross Valve Lift</TD><TD vAlign=top noWrap>0.462 </TD><TD vAlign=top noWrap>0.474 </TD></TR><TR><TD vAlign=top noWrap>Duration At 0.006 Tappet Lift</TD><TD vAlign=top noWrap>250 </TD><TD vAlign=top noWrap>260 </TD></TR><TR><TD vAlign=top noWrap colSpan=3><HR noShade></TD></TR><TR><TD vAlign=top noWrap>Valve Timing At 0.006 </TD><TD vAlign=top noWrap></TD><TD vAlign=top noWrap></TD></TR><TR><TD vAlign=top noWrap></TD><TD vAlign=top noWrap>Open</TD><TD vAlign=top noWrap>Close</TD></TR><TR><TD vAlign=top noWrap>Intake</TD><TD vAlign=top noWrap>15 </TD><TD vAlign=top noWrap>55 </TD></TR><TR><TD vAlign=top noWrap>Exhaust</TD><TD vAlign=top noWrap>68 </TD><TD vAlign=top noWrap>12 </TD></TR><TR><TD vAlign=top noWrap colSpan=3><HR noShade></TD></TR><TR><TD vAlign=top noWrap colSpan=3>These Specs Are For The Cam Installed At 110 Intake CL</TD></TR><TR><TD vAlign=top noWrap></TD><TD vAlign=top noWrap>Intake</TD><TD vAlign=top noWrap>Exhaust</TD></TR><TR><TD vAlign=top noWrap>Duration At 0.05 </TD><TD vAlign=top noWrap>206 </TD><TD vAlign=top noWrap>212 </TD></TR><TR><TD vAlign=top noWrap>Lobe Lift</TD><TD vAlign=top noWrap>0.289 </TD><TD vAlign=top noWrap>0.296 </TD></TR><TR><TD vAlign=top noWrap>Lobe Separation</TD><TD vAlign=top noWrap colSpan=2>114 </TD></TR><TR><TD vAlign=top noWrap colSpan=3><HR noShade></TD></TR></TBODY></TABLE>

 

They will bolt up just fine, but the SD probably will be an issue. I can't say from experience, but I'm gonna say no the computer won't run that motor well. The SD is programmed to run a stock motor (tryin' to keep this simple for ya), and when you change the airflow characteristics (those heads flow more air) the computer can't recognize it and can't adapt. You can either get a computer chip to compensate, which is a couple hundred bucks and not that easy to do, or you can swap from SD to MAF. The MAF conversion is pretty easy, couple hundred bucks in itself but its very easy to do and it works well, do a search for "maf conversion" in the 87-96 forum. I've type the details of this conversion several times on these forums, so you'll find my detailed explanations in the search. It'll tell ya what to do, why to do it,...etc etc. everything...

 

I put the aluminum GT40s with Ford 1.6 roller rockers on the 351W in my Ranchero. This was after reading a heads review in Super Ford, where most aftermarket heads had some fitment issues, all Ford parts seemed the safest path to follow. Stock cam. All parts are supposed to fit together with no problems and seemed to, until later when changing valve springs, I discovered push rods were rubbing in the heads. It appears that the valvetrain geometry is just slightly off, so now It's time to check the geometry with an adjustable pushrod and order up made-to-length ones. Just goes to prove that what appears to be a "bolt on" in reality is not.

 

Well, whenever you change anything regarding the valve train it needs to be re-adjusted lol....I have to buy custom pushrods for my 393 next week....it's just whether or not the head till bolt on the motor and work with the valvetrain, which is true, it will, it's a SBF head...so the GT-40s will work but the valvetrain is assumed to be in need of adjustment after a change like that.