• Hi Guest!
    You can help ensure that British Car Forum (BCF) continues to provide a great place to engage in the British car hobby! If you find BCF a beneficial community, please consider supporting our efforts with a subscription.
    There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Subscribers don't see this gawd-aweful banner
Tips
Tips

Carb Interchangeability Question

Share this page

Monark192

Monark192

Jedi Warrior
Offline
I have a 67 BGT with what are probably the original carbs. I also have a set off a 74.5 B(car long since sold) that were rebuilt by Hap. Can I switch them out?
 
I'm assuming the 74.5B carbs are HIF4s and not the Stromberg carb that came on the later model Bs. The HIF4s should fit. You may need to do some different hose routing but they should bolt right up.
If Hap rebuilt them, they ought to be awesome.
 
In theory. But it means swappin' manifolds, rejetting, blah,blah, blah... I would think it more expedient to go thru the original SU's. And a '67 GT deserves 'em. :wink:
 
DrEntropy said:
In theory. But it means swappin' manifolds, rejetting, blah,blah, blah... I would think it more expedient to go thru the original SU's. And a '67 GT deserves 'em. :wink:
Click to expand...

I'm a little confused Doc (nothing new there though :confuse: ) What is different about the manifold? Why would the HIF4s require rejetting?

I was hoping it was as MarkJ said - just a little hose re-routing. I have these nice, shiney, fully Hap-ed, carbs just sitting on the bench ready to go.
 
That was a changepoint, (74.5) IIRC.

They ~may~ mount up on the older manifold (I don't have both here to compare) but not sure of the angle for the integral float bowl.

Compression was lowered, cam changes, that changes fuel requirement.
 
Thanks Doc. 74.5 got the rubber bumpers but kept the twin SUs I think - at least that's how mine was. 75 got the Stromberg. I never thought of changes to the engine as you mentioned. I will keep whats there.
 
Check intake carb mounting holes and angle on the face of the two manifolds. If they are indeed the same, you might get away with it. But I'd guess you will still need to do some rejetting.
 
They are HIF4s, I don't do Strombergs. The intake are thicker/thinner at the mounting flanges, the heat shield and linkages are a bit different as well, but you can get them to work. The needle and jet hieghts should be close enough to be plug-n-play.
 
What's th' more practical solution, Hap? Go thru th' conversion or fix/set up the originals?
 
If you opt to have Hap rebuild the originals, as said before, you'll not only have an awesome set of carbs, that will not only work like new but will look like new as well and you won't have to modify anything. He rebuilt the ones on my 72 and I can testify that they are the best, bar none. PJ
 
Back
Top