I have just finished my install of a Offenhauser Crossram and two Holley 390CFM on my 383 roller motor. The motor is a roller with a Howards 501/509 lift cam with 292 duration. I have 64CC RPM heads on the car with a 2000 stall converter and a 700R4, along with 350 gears. I did not expect a performance gain, but it woke up this motor. I had a 670 avenger with a RPM airgap on the motor before. I did this more for the WOW factor than performance. Tell me what you think. Thanks Jerry

I have one of those manifolds..have'nt put it on yet..so your saying you noticed a performance increase..I've used tunnel ram's before and it was a big difference from one carb,but have'nt tried the crossram yet..your setup look's nice..

Good choice of carbs. I always hear stories of guys putting on dual 650DPs and then complaining that the manifold is dead below 4500rpm. It's a nice feeling to go for 'wow' and get 'go' too! Wait till you fine tune it a bit. Looks very impressive.

The one thing that I did before I started this install was to read a lot of topic's on crossram installation on this site and ask question to some of the member who had gone down this road before me. Valve cover clearance is a problem, but I managed to get my tall ones on with a allen head 1/4 20 on the rear of the driver side and the front of the passager side. I am still not happy with the kick down linkages and may change it to LOKAR when I change the torque converter next week. The best tuneup so far is to use the driver side carb for the main carb idle adjustment and keep the idle adjustment on the passager side screwed all the way in. I still need input on the adjustment of the carbs, but they were setup for a crossram and has a balance hose between the two vacuum secondary housing. I also made a balance hose between the two carb using the pvc slot. The only issue that I am having rite now is when I put it in gear, the rpm drop down 300 or 400 and if I turn on the A/C it dies. I think that the new torque converter will fix that. I have not been able to tune this issue out of the motor. Thanks for your input and keep them comming, Jerry

Very clean looking install. Love the black.

Good choice of carbs. I always hear stories of guys putting on dual 650DPs and then complaining that the manifold is dead below 4500rpm. It's a nice feeling to go for 'wow' and get 'go' too! Wait till you fine tune it a bit. Looks very impressive.
As a matter of fact,I plan on putting 2 650 DP's on mine..But I have a 406 with Brodix heads and 4:56 rear gears and a 4 spd..ran a tunnel ram with a simular setup 20 years ago and it ran great..pulled very strong on top end..but with an automatic,I can see going with smaller carbs.

One trick on these single plane crossram manifolds is to stagger the jets.

Think of the carbs as having an inside and outside.Rather than left and right.Think of them as a single unit.

Try using inside jets that are slighlty smaller than the outside jets.Just by one size.

Lets see a video of that thing running!

Fantastic job!

VERY cool!

IMO, the air cleaners look dated.

Oh yeah, everything else looks great,

I know about the air cleaners. I am waiting on one to come on eBay for less that $400.00 and I want it to be the oval one so I know that it will fit under the hood. Thanks for all of great support on this installation. Jerry