http://novaresource.org/codes.htm
http://no25.chuckthetruck.com/page3.htmltrucks
SV - 250cid w/manual trans, emission controls
SW - 250cid w/auto trans, emission controls
SX - 250cid w/4-speed HD trans
TA - 250cid w/manual trans
TC - 250cid w/manual trans
TD - 250cid w/4-speed trans
TE - 250cid w/auto trans
TF - 250cid w/4-speed transTS - 250cid w/TH350, emission controls
UH - 292cid w/manual trans
UR - 292cid w/manual trans
UQ - 292cid w/TH350
UT - 292cid w/Powerglide
VQ - 292cid w/manual trans, emission controls
VR - 292cid w/Powerglide
these links might help you. by the quick look I had,yours is a 250.
I am sure the 8" DVD will make it run
much better. regards,Rod