I'm about to choose between these two cams for a (edit: non-roller block) 383. Heads are Edelbrock 60899, 2.02/1.60, Static CR is about 10.3. 3.08 rear, Muncie. Intake Z28 Aluminum, Holley carb., Rockers 1.5.

Head Flow Numbers:
Valve Lift Intake Exhaust
.100'' 63 51
.200'' 124 94
.300'' 181 128
.400'' 227 146
.500'' 253 157
.600'' 253 163
.700'' N/A N/A
Flow Numbers as tested by Edelbrock's SuperFlo SF-1020 flow bench @ 28'' H2O

Roller cam is NOT in the budget and is NOT an option.

Anybody who has direct personal experience with these cams have a good reason to pick one over the other?
(Also- my wife will drive the car occasionally)

 

Did you talk with tech at the cam manufacturer? If you give them all the specs you listed here, they may be able to make a very good suggestion.
Duane

 

Call Comp and ask their tech guys.

 

OR call Chris Straub and get his recommendation..

Sorry Chris I forgot you

 

I'm running the HR version of the XE268 on my 350 with AFR 195 heads and 9.4:1 compression. The cam has a nice lope at idle through my side pipes and it has good low end torque for a fun street car. I shift it at 5500.

If I had a 383 with your compression I would maybe consider the XE274.

 

I also have the xe268 with vortec heads in a 350, between the two I'd choose the 274 with a 383 motor, especially with a manual trans.

 

I ran the XE-274 in my 406 for a month,...flattened a few lobes, and replaced it with the XE-284.
The XE-274 had better throttle response for sure with only 10.1:1 compression, but in the 406 would only rev to 5500, and the idle was pretty smooth. Not what I was looking for, so when it went south, I upsized to the XE-284. FWIW I now run an Isky Z-35 that shakes the fenders and revs to 7000 rpms.

In the 383,....I'd run the XE-274. Break in the cam with outer springs only, and you should be fine......I could not justify roller cam cost either,...still can't.

 

I tried to contact them and several others.... I believe they have all cut their support staff to save money... and I received no response from any of them. I won't be wasting my time with any more of that bucket-list destroying crowd.

Summit racing was the most responsive and helpful. That's how I narrowed it down to only 2 out of 10.

 

I'm sure he is very knowledgeable and would probably help.... but.... I am buying from Summit so I feel it would be inappropriate to expect him to spend time on their sale. That's only fair. CCA-CL12-246-3 $195 free shipping.

 

5500 is fine for me. This should be the last engine I build for this car (vette) so I won't be thrashing it. The idle is a high priority due to my wife driving it. So...if it has a "pretty smooth" idle (subjective) I think I should go with the 274. The heads do not have inner springs... they have those flat spiral wound dampers. They're sort of a faux spring. Suggest I bother removing those during break in?

 

HR roller kits are 2-3 times those for the flat tappet cam kits BUT there are good reasons (BTW-I fought the dollar difference for a long time):

Better area under the power curve
Low risk of cam lope wiping
No real breakin procedure
No concerns with ZDDP oil levels etc

Worth 2-3 time the cost? No quite but wipe a lope once on a flat tappet cam and the price of the HR is priceless.......

If flat tappet cams today were reliable like 30 years ago, I can see going FT but not with the crap cams sold today along with the oil issues

 

for a wifes car with 3.08 gears, the smaller cam might be your best bet

 

I have 3 Vettes and 4 Mustangs... plus I'm retired with virtually no income. The budget is spread pretty thin. Maybe next time around I'll start with a OEM roller block. I had two Gen-1 4-bolt main blocks on the shelf and I didn't want to use 'em for boat anchors. It was a tough decision.

Edit: I'm not a fan of retrofit roller kits for non-roller blocks.
Too "Rube Goldberg" for my taste.

 

It's not going to be "her" car, she will just have to drive it occasionally. I picked up a C4 for her.

 

I get it about the money situation and completely understand! After doing the Retro HR on my OEM L-82 block rebuild, It is really very straight forward now versus years ago. Howard's rollers do not require any different distributor gears any longer...same for the fuel pushrod not different than OEM. The only item left is the funky cam button which after much research before my rebuild is blown way out of proportion and again very simple to install and along with a double roller timing chain makes cam "walking" highly unlikely...Again, blown way out of propportion. Gary of LI uses a procedure used now that prevents cam walking without a cam button....

 

Even if it is not HER car, those heads are not a huge either. I think the smaller cam will have better throttle response and low end grunt for a fun street cruiser.

 

Tom -
I've run both cams.

I had the XE268 in my '64 350 before I rebuilt it and replaced the engine. That 268-cammed engine is now my test bed engine in my workshop, and I use it to test all the carbs, since it's very representative of typical moderate performance cams. This engine has a pair of Dart heads on it and headers. It has a good idle, and pulls good vacuum. The idle has the "musclecar sound" to it, but it's not obnoxious. It pulls good torque at low rpm, and is an easily driveable combination. I never had this engine on the dyno, so I don't have firm hp numbers, but I'd say it is a strong contender as a 350/350 combo.

The last XE274 I installed was in a 400 small block bored to 409. This was in a 4-speed car with good heads, headers, roller rockers, and some nice rotating parts. The cam has a fairly choppy idle, and likes to idle above 850. You need to get the rpm up a little when leaving a stoplight, and it comes on strong in the mid-range - much more so than the 268. But it does like steeper rear end gears - I used it in a 3.55:1 car, and I think that's about the lower limit. The cam will tear your head off on the top end, and makes power beyond 6000 with good heads and intake.

For "comfort driving" I'd run the 268. It's a very safe bet for comfortable performance. If you want to make some impressive power, get some 3.73 gears and run the 274.

Lars

 

Thanks Lars.... always good to hear from you.
I have a set of 3.36's ... and if needed could go with a new set of 3.55's... but then I'd probably want to swap out the Muncie with a 6 speed for overdrive. Champagne taste on a beer budget. This is not an easy choice.

 

You probably won't notice that much difference between the 3.36 and the 3.55, but going from the current 3.08 to the 3.36 would be a desirable upgrade with either of the two cams - you should really consider doing that, even with the stock 4-speed.

Lars

 

it will still sound decent pull well without her complaining about the shaking etc.
Not a fan of that line but if youre stuck on them use the 268

either trans would be great with a 3.55 3.08s suck unless you got a big block