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MattW
07-16-2011, 6:06pm
What diameter is the stock TB on my LS1?

Seeing all these ads for intake upgrades... talking about FAST 90, FAST 92, etc... am now wondering exactly what the stocker measures, if I wanted to get a new intake manifold, but not sure about getting a new TB.

(Trying to make this a better C5 Section by asking questions I know would be answered in 30 seconds flat elsewhere :) )

::: crickets :::

Munch
07-16-2011, 6:43pm
78mm for the LS1 and LS6.

90mm for the LS2, LS3, L76 and LS7.


I think... :leaving:


Got any pics of your ride?

MattW
07-16-2011, 7:17pm
Last weekend -

http://a8.sphotos.ak.fbcdn.net/hphotos-ak-ash4/271153_1658104271256_1796638879_1043428_7986044_n.jpg

Red09C6
07-26-2011, 7:34pm
I was just checking on this during this week. The OEM LS1 tapers down to 71 mm and most "ported" throttle bodies keep the stock size throttle blade. The LS2, from what I was told, uses a 4 bolt body, which mounts to the F.A.S.T. manifolds that are available now (don't know about the FAST 78 manifold) so an adapter is needed to use an LS1 unit on the later FAST's (as well as the fuel rail). I am sending my OEM LS1 unit out to a vendor who bores them to 78 mm and makes a new throttle blade, and also claims it flows better then the BBK 90 throttle body...we will see.