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Original Message
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| You've got a 390IP engine in that car. |
| By Dave Shoe - 04/26/2002 10:06:15 AM; IP 63.233.226.21 |
FPA Tri-Y headers for 390GT engines will be your absolute best bet. www.fordpowertrain.com is the place. Not cheap, but the quality and fit is tops.
CJ exhaust manifolds are also a slick idea, but FPAs fit well and offer great ground clearance.
Since 1968 was the last year of the 390GT engine, you inherited the next version of the motor: the 390IP.
IP stands for "Improved Performance", apparently a new term for Ford which fit between "Standard Performance" and "High Performance".
All 390GT engines were forced to accept the expensive Thermactor emissions package in 1968 (due to the large valve overlap allowing raw gas to pass through to the exhaust), because of a new set of regulations which took effect that year. The 428 took top position in 1969, and also needed Thermactor systems to pass emissions.
Since the 390GT was no longer needed as a premium performance package, Ford ordered (in print) that Thermactor be removed form them, as there was more sales value in reducing costs of the second-tier engine. The only way to accomplish this was to put a regular production cam in the engine. The Holley carb was also replaced with a less expensive Autolite.
GT heads are actually the same as any FE production head. The difference is in the valve springs and associated hardware. Since there were never any dud FE heads cast, all FEs have good heads, though the smaller runners of the "emissions era" heads (first showing up in 1966), make the large runner heads comparatively desirable.
I harp on FPA headers for your C8AE-H castings because those are "emissions era" castings with smaller "velocity" runners. Yes, the same castings are used in 428PI engines, so they are proven runners.
The problem with Hooker headers, or most of the headers, is that they were designed for "pre-emissions" heads which have their exhaust positioned 5/16" higher on the head. The port height is the same on your head, but it was positioned downward in 1966 to make it compatible with Fairlane/Mustang 390 exhaust manifolds (a poor design exh manifold, in my opinion).
FPA makes a header flange for raised-port heads (all 1958-65 heads, C6AE-R castings fairly common in 1966-67, CJ, and all 427 castings), and they also make another flange for low-exit heads (C6AE-J, -L, -U, C7AE-A, C8AE-H, and D2TE-AA (some others also exist).
The FPAs have a great reputation among FE enthusiasts.
Shoe. |
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