Since I haven't had many suggestions from 2.3 talk, I decided to post here. I'm hoping someone has a little experience with the Offenhauser 4bbl intake manifold. I have a 1987 Ford
Ranger (yes, not a Mustang) with a 2.0l engine (same as the 2.3l only difference is the bore size). I have an open chamber oval port head (the good one) from the early 80's mustang 2.3's with lots of work done to it. It is shaved to 55cc chambers, gasket matched port and polished, 1.89" Intake and 1.59" exhaust oversized stainless steel swirl polished racing valves, Dual valve spring set up with 10 degree locks and lightweight titanium retainers. It also has roller ranger followers with a Crane Cams PowerMax roller cam 282/282 duration .450/.450 lift. This set up gives me about 10.25-11:1 compression on my engine and flows real well. I am currently using the Offenhauser 4bbl intake with a Holley 390cfm carburetor but the carburetor seems too small. Just to give you an idea of how it runs, with the stock vacuum secondary spring (plain) the secondaries start opening at around 5000 rpms when in neutral (winging the throttle). This, however, seems to give me the best power. Any lighter or heavier spring and the engine is sluggish (opening too early and disrupting the primary signal, or opening too late and not flowing enough). This tells me that the engine is needing more flow and the only way to get that is to open the secondaries sooner than it should with the right carb. Any suggestions on what carburetor I really need for this setup? I'm thinking of going with a 600cfm, but I'm trying to decide whether to go with mechanical secondaries or vacuum. My truck is a manual transmission with 3.45:1 rear gears and weighs 2500 lbs. I plan on putting 4.10 gears in it eventually, but because of the weight and the type of transmission (manual) I'm looking more towards the mechanical, but the vacuum has it's perks as well (only opens the secondaries as much as it needs).
Here is a video of my set-up and what it sounds like as of now... Yes that is a modified header (work done myself) to get TRUE dual exhaust. Video doesn't do justice for the sound but you get the idea. Let me know what you think of the video and or any carb suggestions.
Offenhauser 4bbl, what size carb? 1987 Ford Ranger 
