D4B Hood Clearance?

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Hueyjockey

Hueyjockey

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I just pulled the motor on my ‘65 Dart GT, 273 2BBL! The plan is to rebuild it to OEM 4BBL specs....for the most part. I have acquired an Edelbrock D4B intake to top it off. The D4B is about 1” taller than the stock 2BBL intake. I was wondering if I will have hood clearance issues with this intake? I can replace the motor mounts with the local parts store mounts that they say are correct, but they’re really not. These mounts are about an 1” thinner than OEM mounts. This will solve the intake issue, but may cause exhaust manifold issues with the power steering box. If any members have experience installing the D4B, I would appreciate the lessons learned! The carb will most likely be an Edelbrock AVS2, 500 CFM.

Thnx...
 
My 2 cents, the DB4's I have seen do not have the threaded boss for AC compressor brackets, is you have factory AC car.
Offenhauser did have those mounting points, but they incorrectly located the throttle cable mounting point to match the 2bbl Chrysler manifold, instead of the 4bbl location.
If you have and desire to use Chrysler kickdown linkage, that also needs some changes for 4bbl.
 
dpalsmeier said:
My 2 cents, the DB4's I have seen do not have the threaded boss for AC compressor brackets, is you have factory AC car.
Offenhauser did have those mounting points, but they incorrectly located the throttle cable mounting point to match the 2bbl Chrysler manifold, instead of the 4bbl location.
If you have and desire to use Chrysler kickdown linkage, that also needs some changes for 4bbl.
Click to expand...
Good info, thanks! Don’t have A/C, so no compressor mounting points needed. Will needed the kickdown linkage, what changes need to be made? Do I need a whole new assembly or can I make the 2BBL one work?
 
Your throttle point on the 4 bbl carb is now forward of the two bbl throttle point. I initially tried stretching kickdown rod with allthread & coupling nut. Better solution was finding 273 4 bbl bell crank assembly which bolts to rear of LH Cyl head. Also correct rod to carb. From bell crank on down, linkage looked the same. There is a Holley Carb bracket to adapt Mopar throttle stud to Holley carb. Can uses same throttle cable, but cable clamp is inboard for 2 bbl and outbd for 4 bbl. I will try to gather pictures later. I recommend you copy and save pictures you find online, to establish what things look like.
 
dpalsmeier said:
Your throttle point on the 4 bbl carb is now forward of the two bbl throttle point. I initially tried stretching kickdown rod with allthread & coupling nut. Better solution was finding 273 4 bbl bell crank assembly which bolts to rear of LH Cyl head. Also correct rod to carb. From bell crank on down, linkage looked the same. There is a Holley Carb bracket to adapt Mopar throttle stud to Holley carb. Can uses same throttle cable, but cable clamp is inboard for 2 bbl and outbd for 4 bbl. I will try to gather pictures later. I recommend you copy and save pictures you find online, to establish what things look like.
Click to expand...
Good advice, thanks. Can’t wait to see the pics!
 
One picture is my early attempt to stretch 2bbl kickdown rod. Others are factory 4 bbl linkage, on Offenhauser intake, and Holley Sniper. Note how the 4 bbl bell crank has different geometry.

273 4 bbl bellcrank.jpg


273 4 bbl linkage on Holley.jpg


273 4 bbl throttle cable.jpg


Early 273 kickdown rod extension.jpg


Holley 4 bbl Mopar bracket.jpg
 
The D4B is pretty flat. I think the only way you'd have hood clearance issues is if a 900 pound fat woman sat on your hood.
 
RustyRatRod said:
The D4B is pretty flat. I think the only way you'd have hood clearance issues is if a 900 pound fat woman sat on your hood.
Click to expand...
:rofl: That image will be on my mind all afternoon. :thankyou:Rusty! LOL
 
On the extended rod, i felt that I was having to adjust length to improve kickdown response, to where I might be restricting my wide open throttle travel. That actual 4 bbl bellcrank looks like it would respond quickly to throttle, than have plenty of travel as the arm arc changes.
Replacing that bellcrank assembly in the car was a real challenge.
If I had not found 4 bbl linkage, I considered slotting the hole in the Holley bracket, where carb stud mounts, to make that arc smaller, moving that stud closer to pivot point. Or find someone to measure 4 bbl & 2bbl, and fabricate a short metal tab to duplicate that forwrad hook on the 4 bbl bellcrank.
My wife found our linkage on A Body Facebook group.
 
dpalsmeier said:
On the extended rod, i felt that I was having to adjust length to improve kickdown response, to where I might be restricting my wide open throttle travel. That actual 4 bbl bellcrank looks like it would respond quickly to throttle, than have plenty of travel as the arm arc changes.
Replacing that bellcrank assembly in the car was a real challenge.
If I had not found 4 bbl linkage, I considered slotting the hole in the Holley bracket, where carb stud mounts, to make that arc smaller, moving that stud closer to pivot point. Or find someone to measure 4 bbl & 2bbl, and fabricate a short metal tab to duplicate that forwrad hook on the 4 bbl bellcrank.
My wife found our linkage on A Body Facebook group.
Click to expand...
Awesome thanks. I’m going to start looking for a 4BBL bell rank assembly. If you have any leads, please send them my way...
 
here is a better picture of what you are looking for.
Might post a wanted here, and also on the For a body facebook group.

273 Dart 4 bbl bracket.jpg
 
Also, some of these 65 273s already ride pretty low to the center steering linkage. Something to keep in mind when looking at the motor mounts and shims you removed. Firm Feel makes a nice dropped center tierod link, but it's a bit pricey. They also do nice steering box rebuilds to make car steering feel modern.
 
dpalsmeier said:
One picture is my early attempt to stretch 2bbl kickdown rod. Others are factory 4 bbl linkage, on Offenhauser intake, and Holley Sniper. Note how the 4 bbl bell crank has different geometry.

View attachment 1715541631

View attachment 1715541632

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Click to expand...
Do you remember where you sourced the 4 bbl bell crank? It is the solution I am looking for. I have a factory 2 barrel car and B4D that I am considering using but do not want to make irreversible modifications. Thanks.
 
Wife asked for it on the Facebook forum and someone responded. Otherwise I would have tried to get someone to measure position of 4 bbl hole where back rod attaches, and fabricate that hook shaped part to bolt on. Use upper 5/16 hole and lower 3/16 hole on the two barrel bell crank. AMS new old stock quoted a throttle cable bracket for $70. Hate to think what that bellcrank would cost if they had it.
 
Hmm. Do you think instead of messing with the bell crank I could fabricate a rod with two bends / s curve to make up the height difference of d4b to stock two-barrel? It might fit behind the last intake runner.
Did you reuse the 2 barrel throttle bracket? I forget if you said. (sorry).
 
The two barrel throttle cable bracket is inboard, and aft, from the mounting hole, think smaller carb. Four barrel throttle cable bracket is outboard, and forward. Also not sure where on intake a DB4 has bolt hole for cable bracket. Should be further forward on a 4 bbl carb, as throttle shaft is forward of center, compared to a two bbl intake. Same throttle cable, so clamp has to move forward.

Less about intake height, and more about how throttle and bellcrank move together.
In addition to the 4 bbl bell crank arm being forward, the hole for the kick down rod is approximately 3-1/4" from the bell crank pivot shaft. The hole for kickdown rod on 2 bbl bell crank is approximately 2-2/4" from bell crank pivot. Since the driven arm on bellcrank is a larger radius for 4 bbl, it has a smaller rotation angle, and does not reach limit of travel, and restrict throttle rotation.

We have Automobilia to attend today; I will try to sketch something out later.
 
Did a quick sketch at work. I believe extending the kickdown lever in this fashion would mimic the 4 bbl bell crank. Fabricate a metal tab of similar width & thickness to the original lever. (Factory 2 bbl lever shown in red). You are compensating for moving throttle shaft forward, so use that change for the hole spacing. Put a sharp bend on your new tab, so it can't rotate when you bolt it tight to the original 2 bbl lever. Existing rod length should work. This gives the kickdown bell crank lever a larger arc, letting you adjust rod, with out kickdown linkage restricting throttle travel.

KICKDOWN EXTENSION.png
 
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