Not sure which edelbrock you have nor its height. The funnelweb is 6 7/8" (above the rail on the block) and their website is
http://parkerracing.com.au/funnelweb.html . They are really good with the cleveland you may want to make contact with them. I think any dual plane (including a modified one) may be to mild for that motor and cam combination. Sounds like you are building a 500hp screamer!