3 AND 4

[Piledriver]

Webers/dells use same manifolds

Linkage might need some massaging.

[GARRICK.CLARK]

Hey Pile you've been giving advise to me for ages now. My engine has had backfire issues for ages now. Well I went to start it the other day after swopping the dells for a single 2" Su carb I had. I turned the key and I just spun over. Didn't even try to start. I sprayed some easy start into it ,still nothing. Swapped the petronix 3 for plain old points and it fired right up. I'm wondering this module was bad from the start and gradually getting worse over time until it finally gave up. I bought it in 2015.

I'm gunna try blowing through the S.U carb and see how it goes.

[Piledriver]

Its not at all unusual for a pertronix or compufire module to go flake before dying.
(frequently only when hot)
I always suggest carrying either a spare or a set of points/condenser.
They're small, and a lot cheaper/faster than a tow.

SUs have a good reputation.

[GARRICK.CLARK]

You never expect new parts to go bad , That's why I didn't really think it was causing problems.
I've got the SU carb fitted.
So , if you can picture this.
I have the dell manifolds fitted. A horizontal intake pipe at the same height as the alternator nut and just in front of the alternator pulley.
A silicone 90 degree bend on either end of the horizontal intake pipe.
This horizontal pipe has an inlet for the carb which is in the middle, so its equal length to the heads.
The 90 degree bends connect to the dell manifolds via a pair of link pipes.
The 3 and 4 90 degree silicone bend WHEN the engine is at idle is sucked in on it self due to vacuum.
The 1 and 2 silicone bend isn't.
Is this an air leak on the 1 and 2 side.

[Piledriver]

More likely just a difference in the stiffness of the bends.
Those aren't typically used under vacuum, they're made to hold pressure...

[GARRICK.CLARK]

Yeh you probably right. I'll look for some reinforced ones.