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JC Whitney sells an intake manifold that bolts on, and allows you to add a 4bbl carb. To your inline six. Have any of you ever, used this or know someone who has?
JC Whitney sells an offenhauser intake. I don't know if they sell both the single and dual plane, but thousands of people have that intake. They are relatively common (as far as performance 300 parts go)...
Vampiro jegs.com has them for 199.99 heres a link to the page. Keep in mind if your gonna put this on go with a header aswell. I use a 600 edelbrock carb on it but have a different cam aswell.
>..... Keep in mind if your gonna put this on go with a
>header aswell. I use a 600 edelbrock carb on it but have a
>different cam aswell.
>
I have the intake mentioned..... I ordered it from jc wjitney only cause jegs was on back order with it when I ordered. I also have the edelbrock 600cfm carb and dynomax headers and the crane cams performax dual pattern cam. The only advice I can give is use half washers on the exhaust side of the manifold to compensate for the thickness difference...... I learned the hard way..... plus make sure you get the "C-series" offy intake..... not the DP.
Okay, I ordered the 390 Holley and the Offy Dual Port intake from Jeg's this morning, I have a Crane 260-H Powermax cam and springs, and the block and head are at the machinists' as we speak.
Now for my question, Why not the DP Offy? The Open Plenum model at JCW is for a much wider/higher rev range than I want, and the specs don't tell me that it will help way down low on the tach.
I am pulling a 18.5 foot travel trailer and the truck has the 3 speed w/overdrive (RUG/RTS? I dunno). As it is now, the rear end is geared way too high and I get a bit of chatter out of the clutch on takeoff, so I'll lower that a bit, and the engine mods should help out a great deal.
Thanx in advance for the reply, hope I didn't waste my money!
I think you did well on the intake adual plane versus an open plane will produce more low end hp and torque on any engine. You shoulld look into a header for sure I have a pacesetter brand which is a dual outlet also. If you do change the cam you should avoid high duration for towing. The thing i do question is the 390cfm as I have used both a holley and an edelbrock 600cfm on my 300 and both worked great with only very minor tuning. But im thinking if you keep the stock cam a 390 might not be bad.
I am not sure exactly how much mine is putting out but I do plan to have it dyno'd at the local Wynne Speed before I do any other mods. I will post the results when I get them.