The internet can be a source of great, useful information. In turn, it can also be a sorce of gossip, rumor, half-truths, and exaggerations. I only give suggestions that are based from my actual, repeated experience. I try not not to post "I heard...", or "my buddy knows a guy who's brother did...", unless I know it is a solid fact. As for me, I was a factory trained Ford mechanic for many years and I have built more hi-performance and racing FEs than I care to remember. I have several FEs that I'm building for customers right now, all 427s and one 428. I will attempt to clarify my suggestions and disspell some untruths.
1) Single plane vs dual plane.
I have used the Dove S/P intake. It makes great power from 4500 to 8500 rpm. It is very big and tall.
I can't verify this about an E-M Cobra but I know it will not fit under the hood of most of the other Coba chassis with even the thinnest air cleaner. The Edelbrock Victor is a tiny bit shorter but still won't fit without cutting the carb pad down. Dove is probabley trying to sell you that intake because it is the only 1-4V intake they make. The E-brock RPM intake is designed to work best between 2500 and 6500 RPM. To give you an idea of how well the E-brock RPM intake works I swapped a ported and re-worked Offenhauser Port-o-sonic single plane intake (THE 1-4V intake to use for a long time) with an out-of-the-box E-brock RPM.
The car was a Thunderbolt replica with 428. We swapped the manifolds the same day at the track and it picked up 2 tenths and 1.5 MPH (11.00s to 10.80s from 118 to almost 120 MPH) THe 60 ft times dropped from 1.6s to 1.5s. Engine rpm was 6200. I think you will be happiest with the Performer RPM.
2) FE
oil system mods.
In PJS50's original post he stated that he wants a 390 capable occasional bursts to 6500 PRM. In a later post he mentions a 7000 RPM reline. This is 427 RPM territory. All 427s have the
oil pump passages enlarged from the factory from the puny 3/8" to 7/16". Hell, a 289 has 7/16"
oil passages! That is a .062 enlargement. .031" on all sides. If your block oil passage can't take .031" without breaking thru you have more serious problems than oil control. I'm not asking you to cut your block in half and weld it back together again, the mods can be done by anyone, with hand tools and that has the ability to rebuild an engine, in about an hour. Enlarge and deburr the oil pump passages, line up the passages in the main bearing holes, and clean up and deburr the oil drainback holes. Make ABSOLUTLEY
sure that the grooves in the cam bearing journals are clean and free of all obstructions. If you plan on a mechanical cam, block off the lifter bore passages. On street engines I normally do not restrict the oil to the rocker arms. Street engines idle a lot. Race engines don't. The extra oil in the top end keeps the valvetrain well oiled at idle speeds and keeps the valvesprings cool. As long as you have an 8 or 9 qt pan, oil volume is not a concern. While on the subject of oil pans, the only reason to run a front sump pan is because you HAVE to for clearance. On a Cobra chassis,
there is nothing but room and one is foolish not to take advantage of a well designed middle or rear sump pan. Armando's
(check search for info) makes a beautiful mid-sump road race Cobra style pan for about the same price as a Canton or Milodon pan.
3) Connecting rods:
Eagle and Scat have been getting a bum rap because they are made in China. Eagle rods are forged in China and machined in the USA. The Scat rod is all Chinese made. I checked my records and in the last 18 months I have bought 14 sets of Eagle rods and 3 sets of Scat rods. One difference I have found between the 2 is the clearances and balance weights of the Eagles are more consistant than Scat. The last Set of Eagles I did where within 2 grams thru the set of 8 The Scats are ususally twice that. One thing that is common between the 2, and I think has caused the biggest problem for the uninformed, is all of the clearances (pin fit, rod bearing journal and side clearance) are all at the MINIMUM
clearance spec, if not tighter. I never have been able to use one out of the box. To me, this is a good thing. I can always take material out easier than putting it in. Example: Joe Schmo buys a rotating assembly kit from XWZ Speedhouse. The kit is complete, crank, rods,pistons,pins, rings bearings, etc. He assumes because the kit is from one place and everything is brand new, he can just slam it together in his new block. It goes togther, into the car, and the first night at the drags he seizes a rod bearing and kicks a coneecting rod thru the block. He dissassmebles the engine, sees the broken rod, and says "Those cheap commie bastard Chinese rods are junk!" It's all cause and effect. The broken rod is the effect but the cause was insufficent bearing clearance. I and the machine shop I use have used dozens of Eagle rods in high RPM and high horsepower engines and have never had one fail due to a faulty connecting rod.
I'll write more when my fingers uncramp
--Mike