I believe it's roccodart that has run the 1" spacer on the RPM intake and found it to be of benefit. I know the Torker II has liked the 2" Super Sucker on the 440"-500" engines we have tried it on. Here are two back to back runs with a Torker II and Torker II w/ 2" Super Sucker.
RPM...............TKR II TQ/HP........TKR II w/SS TQ/HP
3200....................541/329.................536/326
3500....................592/395.................595/397
3800....................597/432.................597/432
4100....................602/470.................609/476
4400....................602/504.................611/512
4700....................612/548.................617/552
5000....................616/586.................621/591
5300....................607/613.................617/623
5600....................585/624.................601/641
5700....................579/629.................594/644
5800....................575/635.................585/646
5900....................567/637.................577/648
6000....................557/636.................570/651