ITB conversion from CIS

So, this is may be onbe or several stupid questions but im knee deep into my Mk1 Clipper restoration, LHD, has cruise control and the AC and heater stuff. She's in bits right now but planning the rebuild. SO, i ditch the CIS and want to change to Webber ITB's……whats the best ones to go for twin 40s or twin 45's? Not 100% sure of the extent of the mods i plant to make yet but dont want to purchase the 40s and then have to upgrade to the 45s. With that being said if i dont do ALL the mods etc will the 45s be too big for her if i only moderatley update stuff, ie cam and headers etc? I think the 45s are better when you have ported head and bigger valves but dont want to buy 40s and then have to buy 45s later.

Also……… now that theres no inlet manifold…… where to all the vacuum hoses go for the ac heating system and cruise control????? 

Your terminology is muddled. Firstly, Clipper has a carb, not CIS (unless its a weird one - maybe non UK? I don't know).

Secondly, ITB = Individual Throttle Bodies - ie, 1 per cylinder, 4 in total. Then you go on and reference twin carb setups.

LHD, A/C, CIS and cruise control = US spec?

Car is a USA spec car therefore not UK. clipper is what I call it because it has the kit and I'm from UK. However, it's a Mk1, LHD, USA car. It's has side running lights too, the UK cars don't. Anyways , yeah its not a UK car.

On the throttle bodies, yeah I probably muffed that up. I'm looking for a twin 40 or twin 45's throttle body kit. Or if individual throttle bodies are better would like to know what options we have there?

The other question is still about the vacuum hoses etc……thanks

If you removed the standard stuff then installed ITBs, you'd also lose the reliable vacuum supply and also lose any hope of a meaningful vacuum value to be read by a sensor (you could fit something to one or more of the ITBs, but it would pulse a lot). Forget about the cruise control. Not sure on the implications for AC and/or the brake servo either.

ITBs - individual throttle bodies - don't inject fuel. That's done separately (by fuel injectors), ie its also a conversion to fuel injection. However due to the unreliable vacuum reading, they normally use alpha-n logic (throttle position and engine speed) than MAP or MAF (manifold pressure or airflow).

I guess there are some 4 carb options but you're well into customising something off something else (a motorbike?) with custom inlet manifold, linkages, choke?, rejetting, etc.

What's the reason for the ITBs? Does it have a transparent bonnet?

no transparent bonnet. just like the throttle bodies. So looks like ITBs are not what im looking for. Cars bee torn down and stripped right now and is away getting straightened. had some minor damage, anyway, ive been scouting around and think im going to try the following setup so any experience / help would be appreciated. Looking for an ABA bottom end, going to strap a stage 3 (8valve) ported head with a 280 cam on it and go for the twin weber 45's and prob a, 4/2/1 headers and a 2.5" exhaust. Might need to change out the chokes on the 45s but think thats fairly easy to do. Any idea of bhp that this might produce?

Also, assume i will lose the vacuum when changing to the 45s so will prob have to install a vacuum pump for the ac controls and brake assist etc. 

Its still an 8V counterflow so around 140bhp if you can get it set up properly. It ideally needs a rolling road session or two, and someone who understands carburettors, to do this.

No idea on whether you will have a decent vacuum or what to do without one for the stuff that needs it.

I'm not sure if I'm allowed to post the link, but I am selling the inlet manifold and twin Weber carburettors to fit a 1.8 DX engine on ebay if any use to you

Item number mate

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https://www.ebay.co.uk/itm/164943893115?mkevt=1&mkcid=1&mkrid=710-53481-19255-0&campid=5338273189&customid=&toolid=10001&pub=5575378759&icep_ff3=1&ipn=psmain&icep_vectorid=229508&kwid=902099&mtid=824&kw=lg