Register a free account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members through your own private inbox!
Unfortunately I don’t know the part numbers for the springs as they only come as part of the selector hub for 1st2nd gear.
Your only hope is to find another box and strip
It to plunder it for parts.
Ford cosworth Amal valve was by far the most reliable boost controller I used. Just different sized drillings for the insert into the valve needed. Bit trial and error at first, but never had one fail, and that was running 2bar+ boost lol
Unsure how well the Grp n timing would work on the bp270’s tbh.
Regards what’s best, it all depends what you’re after. Peak bhp then 197, but in my opinion you get better drivability from Grp n on standard cams.
If you click on my link in my avatar, you can see 230bhp with a 197 head and inlet fitted to a 172 block. It may have also had some quite lairy items inside the engine as well 😂