Intake Seating & Carb/Distributor Qs

[CV355]

My father and I pulled the iron intake off my 428CJ to prep for installing an Edelbrock dual plane.  Wow that thing is heavy.  There was a 0.030"-0.040" step between the head valve cover plane and the iron intake valve cover plane that I could never get to seal, so I figured I could upgrade the intake while addressing the issue. 

We test-fitted the aluminum intake on and the step was far less pronounced- maybe 0.015"-0.020" max.  Looks like I still have to get the valve cover plane machined down to match. 

1)  Is there anything I should be aware of or cautioned on before having this performed?
2)  I've read that the Holley 735 on this engine is simply the best for the street.  I'd like to preserve the original and get a polished or chrome 4150/735, but how do I ensure it is jetted the same as the original?  Is there a modern mfg direct-swap available?
3)  I have a Hayes (Stinger) ignition controller and 2-wire solid state distributor (no vacuum advance).  Some of the wiring is deteriorated, and the ignition controller is epoxy-filled, so it's not serviceable.  What would be closest to a direct swap? 

Not looking for performance, just reliability and a clean engine bay on this one.  Period correct is preferred, but I'm not totally opposed to modernized components.

[jayb]

Most of the time the valve cover rail is not surfaced on the intake, it is the intake face.  Take the same amount off the intake face as you need to remove from the valve cover rail to make it fit, in your case 0.015" to 0.020".  The reason that most places don't machine the valve cover rail is that it is at a 13 degree angle from the intake face, and there is no easy way to fixture that angle at most machine shops. 

[Drew Pojedinec]

Do NOT swap that 735 for a modern carb. If you cannot do it, have a pro rebuild it.
If you really want to save it and run something else I’d get an older 3310. 
Jetting is air flow through the venturi dependent not engine specific.

[CV355]

Most of the time the valve cover rail is not surfaced on the intake, it is the intake face.  Take the same amount off the intake face as you need to remove from the valve cover rail to make it fit, in your case 0.015" to 0.020".  The reason that most places don't machine the valve cover rail is that it is at a 13 degree angle from the intake face, and there is no easy way to fixture that angle at most machine shops.

Hmm, that would definitely ensure the ports match...  Glad I asked! 

Do NOT swap that 735 for a modern carb. If you cannot do it, have a pro rebuild it.
If you really want to save it and run something else I’d get an older 3310. 
Jetting is air flow through the venturi dependent not engine specific.

That's what I've been reading everywhere, seems like everyone is in agreement.  I just wasnt sure if there was a "modern replica" that I could throw on and not feel guilty.  This carb isn't in bad shape and was recently rebuilt. 

[blykins]

I have had to cut the valve cover flanges on intakes quite a few times.  In my mind it's necessary on some situations, where the step is something large, like .050.-060" and the ports line up really well already.  The only thing you have to watch out for is what tooling your machinist uses to do it.  On some surfacing mills, the cutter will hit the intake runner or plenum. 

If there's only .015-.020" discrepancy on yours, I wouldn't mess with it.  The gasket will make that up. 

[Stangman]

I know there are a couple of carb guys on the forum but give Drew a ring and get that carb done right.

[CV355]

I had some time last night, so I checked the new manifold vs the heads. 

Valve Cover Rail (intake):  0.095" high
Pushrod Holes:  Concentric, looked fine
Bolt holes:  Concentric, bolts fit nicely
Port Depth: Within 0.020" based on scale measurement
China Wall clearance: Same as previous, worked fine

Basically, it looks like everything lines up nicely except for the valve cover rail.  If I get this machined so the rail matches by machining the intake face, it'll negatively affect the other areas that are currently aligned.

Does anyone have any CAD (2D or 3D) of a head, gasket face, or intake side?  I am thinking about manufacturing a steel shim that matches the profile of the valve cover face on the head and appending it there to make up the difference.  That, or if anyone sells a 3/32" thick valve cover gasket, it would fill that gap perfectly.  Any other ideas?  It looks like the previous owner had it sealed up fine with the same gap on the stock iron intake by being generous with silicone on a cork gasket. 

I don't have the budget this year to pull/replace or machine the heads unless my motorcycle sells.

[blykins]

We cut the valve cover rails all the time......it's not a big deal. 

[CV355]

We cut the valve cover rails all the time......it's not a big deal.

If I have them milled down 0.095", they'll be dead on and everything else lines up.  If I get the budget to replace the heads to drop CR a few tenths, will I have effectively made the new intake junk? 

[blykins]

That's hard to say.   I've seen brand new intakes vary by quite a bit. 

But, measure twice, cut once. 

[CV355]

That's hard to say.   I've seen brand new intakes vary by quite a bit. 

But, measure twice, cut once.

Absolutely.  I'm trying to see if I can get a machinist to visit me at my garage so we can get two sets of eyes on it.  I've done port matching and adapters before, but nothing on an intake that requires this level of alignment.

[My427stang]

I also put a dab of silicone on the mismatch if the ports line up OK....they key is intake/head surface sealing, the v/c rail isn't tough to seal

[CV355]

I also put a dab of silicone on the mismatch if the ports line up OK....they key is intake/head surface sealing, the v/c rail isn't tough to seal

Intake ports and head look like they should be fine.  I'm going to do the measurements today after work. 

This mismatch is rather pronounced.  I think it's what lead to the original V/Cs being warped and allowing oil to pool out onto the headers back in May.  I got 500' up the street when the engine bay billowed smoke.  Even with the engine off, I could see the remaining oil wick down and out a gap.  It doesn't help that I had the FelPro rubber gaskets that don't fit worth a dime. 

We straightened out the valve covers and tried re-sealing but it still leaked quite bad. 

[Heo]

On my last streetmaster one corner was something like that
I built up a "ramp" with TA 31 on the head then put TA 31
on the gasket and glued it to the head still leakfree 2 or is it
3 years later. Edelbrocks "felt" gasket
 

[CV355]

I took more measurements last night and what I found wasn't good news.  I had a machinist visit and we checked a few areas again, looks like only some of the pushrod holes and bolt holes line up, which means I have an angularity / parallelism issue.  My guess is that the original CJ heads were machined far more than I originally thought.

I guess this pushes the build plan in a different direction, might have to swap heads if I don't want to chase the machining down the rabbit hole.  I know the original intake matches up everywhere but the valve cover rails, so I may just pull the heads, preserve them, and swap in something new that'll also drop CR a little.

I'm considering the BBM heads at 75cc. (fixed)