I have a 71 twin port 1600 in stock condition re built 35000ks ago with a vaccum distributor. My current standard carbi is in need of a rebuild with bad flat spots.

I do have a decent set of headers added. Is it worth replacing the existing carbi with a set of dual carbis and if so what would be good value for the weekend driver with just a little more pick up wanted?

First I'd be checking that the vac can and advance plate in the dizzy are both working properly and then if the throttle spindle of the carb only has minor play in the shaft then a clean out and rebuild kit could be all that's needed to get her working well again.

Probably a good idea to do a compression check on her too to make sure the engine is in good order.

If you still wish to go down the twin carbie route then weber 34ICT would be the simplest option followed by Kadron 40's. Next up gets expensive quick but would be baby dells or webers with 36IDF or DRLAs.

I'd also scour the UK forums for the ICT's and Kadrons just cos they're more bountiful over there and so should be much cheaper to buy plus shipping from the UK is pretty cheap especially if you use Transglobal Express. They use couriers unused allowances to sell the unused space cheaply

Thanks. Great advice I'll do that.

Buy an EMPI HPMX kit from Cip1.com bolt on and go!!

I'd suggest original Webers as heard many say the HPMX casting quality is pretty poor and buying from CIP1 is expensive especially with overpriced shipping.

The dizzy is working fine, but the accelerator pump is suss. The compression is an even 145 all round which I hope is ok for a 35000 k motor. Does this fit the bill for a twin carb? Or would a rebuild of the current carbi give the extra pick up?

145 compression is good so engine sounds good from that perspective.

As for the dual carbs. Well even the ICTs will give you more oomph and if set up well should give better MPG too over the stock carb. However, for the cost of a rebuild kit and can of carb cleaner then fixing the single carb is rather economical compared to 2 carbs, manifolds and decent linkage. Main thing is the throttle spindle needs to have nearly zero wobble in it as a worn spindle bore can cause excess fuel to leak out but also introduces unmetered air and this leans the air/fuel mixture out and will lead to erratic running of the engine including flat spots but the flat spots can also be caused by faulty pump jet and partially blocked jets and jet galleries.

Thanks, that rebuild solution and linkage sounds really helpful and the path to go down. Overall she runs as sweet as a nut.

No worries. Good luck with sorting her out. Hopefully just the rebuild will have her running smoother than creamed butter