Thank you for your comments. I don't know but the diagram doesn't appear in the following link http://www.minimania.com/article/762/SU_CARBS_-_Connection__HIF_type. Is it same for you? Anyway, I 've read some posts of GT6 owners regarding the driving improvement by replacing the stromberg by SU HIF. Actually I am happy with my strombergs, except when my engine is cold, I need to adjust the starter with careful to keep a correct mixture. My car is standard, so... may you're right. Regarding the clearance under the bonnet, I found this cap: http://www.7ent.com/products/dashpot-damper-cap-cud2904.html otherwise the easiest solution is to file the cap. GT6boy, may I ask you what is the ral code of your grey paint?