These fabricated necks are designed to adapt our 100mm universal throttle bodies to 4150/4500 carburetor flanges. They feature 1 x -8AN and 2 x -6AN ports. Throttle cables can be mounted with the use of a Proflow throttle cable bracket (PFECB4150BK or PFECB4500BK). For the mounting of GM LS throttle bodies it is recommended to use the PFETBLSADP3 adaptor plate as sealing is improved with an o-ring. The use of a thread sealant on the throttle body mounting screws is recommended to reduce the likelihood of leakage under pressure. The total hight is 165mm, with the upper flange measuring a width of 137mm.