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So I just bought a 9425-B on ebay. Hoping to put this on the 58 312 in my 57 F250. From the quick reading I’ve done it looks like a 4150 400-600cfm Holley-w-a port matched 1” spacer may be the way to go. Just want to hear from a couple folks in the know that I’m on the right track. My buddy says definitely go vacuum secondaries? We’ll also be throwing on a set of Mummerts Rams horns for a little extra exhaling. Thanks Fellas.
i ended up with the machined 4bbl intake, a 2 inch 4 hole spacer and an Edelbrock 600 performer carb (vac secondaries). I would have gone for the 600 cfm summit carb but I had already purchased the Edelbrock 12 months earlier.
i ended up with the machined 4bbl intake, a 2 inch 4 hole spacer and an Edelbrock 600 performer carb (vac secondaries). I would have gone for the 600 cfm summit carb but I had already purchased the Edelbrock 12 months earlier.
Thanks Dennis, so you took the intake down just enough for everything to be uniform flat? I assume you opened up the 4 holes to the 2 ovals in the intake? Did you port match the radiuses from the spacer to the intake? After reading the links I believe I’ll go Holley 600cfm vacuum secondaries, that sounds appropriate for my application of basically stock 312 w Rams Horns?
Yeah I did (the machinist did) take it down just enough to be flat. He also match the radius. I gave him my 2inch 4 hole carb spacer and he sorted it out.
with the added height of the carb spacer I did have to bend the pedal linkage to the carb for it to work.
the 600cfm summit carb seems to be the choice. Don’t forget the 2 inch spacer. I went with the straight 4 hole (as it was cheaper) but would probably gone for the 4 hole tapered just to get the full potential gains if I did it again.
do you know for certain 100% that the engine is a 312? Sometimes people will just say it’s a 312 when selling. The only way to know for sure is to remove the oil pan and look at the main caps to see if they are marked ECZ. Have a read of Mummert’s link below
Yeah I did (the machinist did) take it down just enough to be flat. He also match the radius. I gave him my 2inch 4 hole carb spacer and he sorted it out.
with the added height of the carb spacer I did have to bend the pedal linkage to the carb for it to work.
the 600cfm summit carb seems to be the choice. Don’t forget the 2 inch spacer. I went with the straight 4 hole (as it was cheaper) but would probably gone for the 4 hole tapered just to get the full potential gains if I did it again.
Gotcha, so basically 1 or 2” depending on preference 4 hole 4150 spacer; and tapered or strait again depending on preference. Before you linked that intake/carb info I actually did some reading. It sounded like people were talking about 1/2” spacers vs 1” spacers. Why did you decide on 2”? And did you use a phenolic spacer?
see below from Ted’s dyno run results.Yeah I went with the phenolic spacer.
also just looked at the photo of your engine on the engine crane and it looks like the road draft tube is factory cast blanked off which would indicate the block is 1960 up. I’m pretty sure Ford started doing this from 60-61. That might have only been for the trucks though, someone please correct me if I’m wrong.
see below from Ted’s dyno run results.Yeah I went with the phenolic spacer.
also just looked at the photo of your engine on the engine crane and it looks like the road draft tube is factory cast blanked off which would indicate the block is 1960 up. I’m pretty sure Ford started doing this from 60-61. That might have only been for the trucks though, someone please correct me if I’m wrong.
Very interesting. I wish I knew more about that tapered spacer? Like, is it fully custom or off the shelf? Also I would like to see the Torque and Hp curve. I’m not interested in up top numbers. Useable torque is my main focus.
Yeah I was told 58 T-Bird but who knows. My buddy who built it is a fairly savvy ford guy..
Not sure about the tapered spacer but summit has them. You would just have to measure the intake outside diameter and compare it to the spacer. The main thing is to make the intake manifold modification, according to Ted it gets the “best bang for your buck”.
next time you have the oil pan off have a look for those ECZ main caps.
The tapered spacer in that test is probably not what you want to use. These 4-hole tapered spacers are geared toward higher rpm performance because the design is such that while they do have for holes on top, they are effectively open on the bottom, making them behave more like a typical open spacer, although they do tend to be much better than a typical open spacer. If you have the money, by all means, try one and see how you like it but you will probably be happier with a typical 4-hole spacer or a divided spacer, both of which maintain the dual plane functionality of the intake, which helps low end and is generally what you want for street use. In that same regard, if you have the money try different heights of different styles of spacers, or even combinations like 4-hole stacked on divided.
Thanks Charlie, valuable input. I think I’m gunna go with a 1” 4 hole phenolic and call it good with a decent tune up. I’m not gunna fuss about a couple FT LBS here or HP numbers there. Turning the key and enjoying the ride is the name of the game.
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