I got the 4130 CrMo tubes today from ARIGO. 7 tubes in size 3/4-.049. For connecting to firewall steel plate .125 and tubes 3/4 x .188 Lower FW mounts is a round 50mm dia steelplate , the thickwall tube is cut to 50mm and inner diameter are drilled up to 13 mm 45mm in. Upper FW plates are cut to be 40x100mm size. Measured and positioned to assembling jig rear side. Engine mount pins are connected to front side of jig.
