Heres the engine:

355 World S/R 1.94/1.5 Heads ported(I am shooting for 225/170@.500 Lift)
9.6 CR
Holley 650 DP
Dart Sportsman II Dual Plane Intake

Tremec TKO 5-speed with 3.42 Gears...cruising at 65 @1900rpms.

The cam I have now(203/212@.050) provides all the bottem end I need but I want to make sure I do not overcam this thing and have it act sluggish in 5th gear. What considerations do I need to take into account when picking a cam for use with overdrive?

I am looking at 2 solid cams, both Comp, both are the new extreme energy lines that are the solid equivlanets of the hydro XE line. Here they are;

xs262 solid 224/230@.050 .477/.488 Lift(~.460/.470 w/ Lash) AND;
xs268 solid 230/236@.050 .488/.501 Lift(~.470/.480 w/ Lash)

Now it is my understanding solids 'act' 6 degrees or so smaller so these cams aren't as big as they look. They are also tight lash solid cams(.016) so if I do overcam the engine I can open up the lash to .022 and make the cam act smaller...would opening up the lash this much have a significant seat of the pants difference on the low-end?

Obviously the smaller cam would be better for crusiing in 5th but just how bad is the 268 gonna be on the highway? In the end I want to be able to cruise fine @1900rpms but get the fastest 1/4 mile time I can. Right now with unported heads the the tiny cam I'm at low/mid 14s....I want low/mid 13s with the ported heads and cam change.

Thanks for the help.

I think my combo will be a useful comparison because it is so similar.

355 w/9.5 compression
Dart IE180 heads
Edelbrock Performer RPM Intake
Holley 650DP #4777
200-4R overdrive tranny
2000 stall, lockup converter
3.42 gears

I am currently running the XE262, 218/224 and .462/.469

Car idles very smooth, lots of low-end torque, cruises comfortable at 2000 rpm with the converter locked up. ET's normally in the 13.75-13.90 range at 97-98 mph, and a best of 13.65 at 99mph.

I am removing my engine/tranny over the winter in order to have the tranny freshened up, and I am going to try a new cam in an effort to get a little quicker ET's without sacrificing driveablity. I am considering the same XS268 solid cam that you mention. I am also going to get an opinion from Harold at Lunati/Ultradyne.

I have really enjoyed the XE262 as a nice daily driver/occasional strip combo, and I think you'll be happy with either of those two cams.