Are the aftermarket carb rubber mountings any good?

[Beans]

... If you happen to still have the measurements somewhere, i'd like to kindly ask you if you can send me them ...

You really should pay more attention to answers that are given to your questions
If you follow the link to my weblog with the correct label you'll find a screen shot showing all necessary dimensions for alloy mounts

[Beans]

... to find out if there's some gain to achieve with a different airfilter box. If so, i'll surely post my findings here.

There probably is a some gain in redesigning the air box. I used to have deep K&N filters with ram pipes inside them.
As these became to noisy on long runs I decided to combine an original early air box with the ram pipes and move the filtering (K&N) to a position just in front of the radiator.

[sydney.wedgehead]

Looks like some fine work you have done there...

Is the manifold setup for 1.75 or 2" carbs/throttle bodies?

Has anyone flow-tested the difference running HS6 vs HS8 on the OEM Sprint manifold?

[edgyWedgy]

Sorryy.. haha
I found them and i have drawed it in Inventor already. Ram air from in front of the car, just below the bumper would have an even better effect right? :p Although i guess the float chambers won't like that pressure above ambient without some modification...

[edgyWedgy]

Has anyone flow-tested the difference running HS6 vs HS8 on the OEM Sprint manifold?

Even while the flow will most probably be better with HS8 carbs due to their bigger size, there's the risk of surging.
If i remember correctly, if too little air flows through the carb it'll give a leaner mixture, especially while accelerating.
I don't know if that's the case here already but a twin HS8 setup sounds a little big for our 2 litre engines..
If you don't mind losing a bit of the authentic character, and volumetric efficiency(plus much more things) is everything for you, you should go EFI.(i plan to do so) A plain throttle body without that SU damper will restrict a lot less while accelerating.
It's the thing i hate most about SU's, but their simplicity makes up a bit for that.

[sydney.wedgehead]

twin HS8 setup sounds a little big for our 2 litre engines

Plenty of Sprints ran dual 45 DCOE and the top Sprints here, and in the UK, ran dual 48 DCO.

My attitude is that the wedge deserves the best induction you can give it that is fit for purpose, and so I want a fast street and track car, in the spirit of the Singer 911.

YMMV.

[moodyblue]

Just standard 1.75 sprint carbs.

[dursleyman]

Just for information, I bought my alloy mounts from the Dolomite Owners Club.

They sell the 1.75" for £67.99 and the 2" for £69.99 - but you have to be a member.
I joined for their forum expertise on Sprint engines and the parts.

[MikeRotherham]

A gentleman by the name of Anthony Rhodes in the US used to manufacture them.

If you want to see if he is still making them you could try emailing him, pm me for the email address or you could get it by googling. The domain name was comcast.net

[jeffremj]

Has anyone flow-tested the difference running HS6 vs HS8 on the OEM Sprint manifold?

I refer you to this image, as taken from an old SU tuning book I have. Just assess your power output needs and see what carb setup is best. For example, 2 HS6 carbs are good for up to 170 bhp, but dual 2" carbs would seem better at that output. But if you consider that standard generic 16V 2 litre engines with ECUs only get around 150 bhp that figure is probably all you can get from a mildly breathed upon 16V Sprint engine and so HS6s are perfect. If you want to get to 200bhp and beyond like Honda, the engine needs to spin to over 8000 rpm with the appropriate airflow - not cheap and without variable valve timing, not user friendly.

[edgyWedgy]

@MikeRotherham I just may have found a guy that can make them for me. I have sent him an email just now, so i'll wait for his response.
If he can't do it, your guy may be the a good alternative, in that case i'll pm you, thanks.

@Dursleyman I'm not a member(yet), and i can't wait a year for those mounts... :p They're priced really good though!
As mentioned in my reaction here above, i may have found a guy that can make them for me. If so, my problem would be solved..

[Beans]

... Ram air from in front of the car, just below the bumper would have an even better effect right? ...

Indeed the more air you get in the engine the more fuel you can burn = more power
But as you also pointed out, you do need air velocity over the jets for SU's to work properly.
And for the average (tuned) TR7 engine 2" SU are far to large (actually in comparison to the HS6 the HS8 is 31% larger)