mag drive

have a summersbrothers front mag drive on my bbc..right now i have a 3" offset drive on it..did this because when first built eng it was for door car and needed to move mag 3" out from block to clear my frt bars on chassis..mow have eng in fuel altered so don't need offset for bar clearance...can i come straight out of summerbrothers front mag drive with my big cap mallory supermag 111?willcap clear my heads?also is the summersbrothers frt mag drive use std deck drive for mag or a tall deck drive?will sell my 3" off set drive if mag clears my heads without it..

 

I will tell you our setup and hopefully it helps you.
Ours is a Pioneer front mag drive which I've been told is extremely similar to Summerbrothers. If memory serves me correctly our magneto base measures 6 5/8" from bottom of collar to bottom of aluminum/top of gear (I think this is tall deck).
We run a SM IV with the large cap and there are no cylinder head issues when it is all assembled, but you can't pull that head off without pulling out the mag (I wish this was different! grrrr)
I did have to refabricate that area of the valvecover for more clearance, but these are aluminum fabricated valvecovers so they stick out more as there wall is on the outside of the gasket to give more valvetrain clearance.

 

Ditto on the Pioneer. JW

 

i use a summers drive with a 44 msd & it just clears the vale covers.its the small cap mag. as for the base,mine is a short deck length base.i've had it since 2000 so i dont know if they have changed any besides it being billet now(mine is a cast piece). hopefully that kinda helps

 

would you have pic of how much had to modify valve cover?hotrodharley@wirelessbeehive.com

 

YES;THANKS;helped on drive..mine is aluminum but don't think it is billet;;

 

call me if you like and i can try to help you out some more. 408-887-1504 brian