Got a few questions sine I see soo many people running this cam and cant find any good testomonials just BS "powerfull cam for Big blocks, great power upgrade for small blocks" Yada yada..

How is this cam? Good low end grunt? How's the upper rpm range, when does it stop pulling?
Anyone pass smog with this cam?

Were looking for somthing fairly mild upper RPM wise but makes a huge difference down low. RPM range were shooting for here is idle-5500ish but will sacrifice some upper potential for tire squealing tq with a standard bore 350, TH350, 2200 stall, 3:23 gears.


Thanks!

 

What heads,carb.and intake are you using.You might want to try
the Crane H-272.It pulls really hard from idle to 5500.Or if you
prefer Comp Cams try XE-262.

 

I run that cam in my car and love it. Don't worry about torque with the 268 because you'll have plenty of it. Also, I run vortec heads and 1.6 roller rockers. I don't know if it's because of the roller rockers or not but my cam pulls to 6500 easily. I'm glad to see your running a 2200 stall. When I put that cam into my engine with the stock converter it hated it. It really needs a mild stall. The idle sounds good also. I don't know if you'll pass emissions with it though.

 

Depends on which 268 you're talking about. The xe268 has plenty of low end to 5300/5500. But I'm running 4.10 gears, also had this cam with 342s. I wouldn't use it with 323s. I also had a 2200 stall in it for a while, went back to an astro 4.3 converter. I like it much better. My GTA is my daily driver [work car]. I also have the same cam in my 77 T/A , 400 Pontiac. Completely differant, with 323s it'll melt the tires.

 

I just helped a friend build up a ZZ4 clone (113 vette heads and a .60 over 350) with a carb...now we used the XE274, which is just a bit bigger...I have to say that it idles a bit rough, around 1000 rpm and has a stock Th350 convertor, th350 trans and 3.08 non-posi rear end...which translates into dead performance off the line.

However, from about 1700 and up, the thing screams...which to me means that the XE268 would be the perfect cam for this setup. As long as you are running decent heads and a slightly higher stall...you should be happy.

Good luck...

 

My friend has the XE274 in his '69 in a 350. It has a cool idle.
*Brump-brump-brump*

It would reap havok with a ECM though.

I have the 280H on my '72 and it doesn't have near the idle his does, and he only has a little more duration on the exhaust (236* opposed to the 230* on mine). They have the same LSA, and the same ICA.

Although because of the 6* extra duration does add 3* of overlap @.050", but other than that, I can't explain it.

Of course his does have the "accelerated ramp angles". I dunno.

I'd say if you want a little flatter torque curve, get one of those XE262 4x4 cams instead of the regular XE262. The LSA is spread a little farther apart (111* instead of 110*), and the exhaust has just a little more duration (about 2*) and a just a wee more lift.

 

the 268h non xe cam doesn't have a gob of torque below 2000 rpm but as soon as it hits, then hold on cuz it's pulling to 6000 with a flat torque curve. it wil do the brump brump brump at cold idle till it warms up then you can tell it has a cam but it's not reallt noticeable. the xe268 cam would be a better choice.

 

Sorry for the confusion. Yes, We were going for a 268XE cam. The rest of the mods we were planning like AM carb, this ones a Q-jet currently are in limbo because it needs to be smogged one more time. Any real good EGR friendly replacment manifolds that accept SqB and SpB carbs? The heads are ported 601's currently at the machine shop getting fitted with 1.94 intake's, screw in studs, guide plates and a good set of springs. We left the spring choice up to the machine shop. Interesting note on the 601's. They are actually better then the 416's . The runners are way cleaner and the valves arent as shrowded. It took alot less time to open these heads up then the 416's and dident have the freaking bumps in every port, so there going to be my budget choice from now on.

Gotta order all the parts by monday so.

 

Well ordered a 12-242-2 today 268XE. Specs look killer. I just dont see how this is going to make great low end power like the claims. My Vett cam is kinda a mix between this 268XE and a magnum 270H and its flat dead until 3k and thats with 3.42's and a 5 speed but I like more top end and thats what I usually build for.

I can still change the order by monday so guys help me out here.

 

Heres a link with a dyno sheet of my engine with the xe268. My setup is a little different than yours but you'll get an idea of where the power is. These are rear wheel numbers.
https://www.thirdgen.org/techbb2/sho...hreadid=185715