Not for the 'Velle but for my S-10. It's not fast enuff anymore. Tell me if this combo will work or not:

350 bored .030, flat tops I think and c.r. is around 9:1...block is not decked
GM 993 heads, roller rockers
Comp cam XE274 cam
Weiand action plus dual plane intake
Holley 600 cfm v.s.(also have a 750 cfm v.s. I can use)
Mallory HEI
Hedman specialty headers, 1.5 primaries, 2.5 collectors
True dual 2.5 inch pipes, H pipe, dual cats (gotta have them), Flowmaster mufflers
TH350 tranny, 3000 stall converter, tranny cooler
3.42 posi rear (may upgrade to 3.73)

Truck weighs 2700 lbs curb weight and is not used to haul or tow anything heavy. Wanting to run the engine between 2000 up to but not past 6000 rpm.

Not looking to do a head swap at this point. Can't upgrade the headers either so I gotta stick with what I have.

Based on the info given do you see any pros/cons?

Also what would be a good guestimate of HP and torque from this combo?

Too much cam.

Don't go over 220° of intake duration; otherwise, you'll end up with the classic no-compression/too-much-cam syndrome we all grew to know and love in our rivals (since we knew it made them easy to beat), in the 70s and 80s.

Wierd. I called Comp cams and this is the cam they actually suggested. I gave them the same info too.

What's the biggest XE cam I can go then? I want to stay hydraulic flat tappet.

With OEM 993 heads? 262XE and no bigger, IMO. You don't have enough CR or port to make anything bigger work.

Yeah but wont a flat top piston, a non decked height and a 76 cc head make about 9:1 c.r.? And isn't a 9:1 c.r what's needed towork with an XE274?

9:1 at most. With a stock deck height, flat tops, and 4 valve relief pistons, you may end up around 8.7:1.

The heads really won't work well above 5000-5500 rpm. When you get up into the area where the XE274 starts to "work", you be running out of head. You'll have an engine with a soggy bottom that will still be all done at 5500 rpm with that cam, IMO. Why not try to maximize the power in the usable rpm range with a smaller cam? It will have more bottom, better gas mileage, and be more fun to drive.

Because I need something to help me keep up with the Camaros and Stangs. And I don't wanna use nitrous.

I think the current cam is a Powermax truck cam. Pretty good midrange and low end. But it's not as peppy as I'd like it to be. It's tuned perfectly too.

A light truck doesn't need much torque to push it. Too much only sends the tires up in smoke.

Comp says the XE274 is good from 1800-6000 rpm. I figured this cam plus a good 3k stall converter oughta give me some pretty good ummph.

I basicly wanted more go without having to rebuild the entire engine.

So the heads are no good past 5k eh? Hhhmm...how well do the Trick Flow 23 degree heads flow? What rpm are they all done by?

Are you going to use cast or hyper/forged pistons?

I'm asking because cast pistons will put you down at 8.6-8.8:1 with the smallest shim gasket available (.015 X 4.100). Then you'd have a slug, trust me, i have a cast piston rebuild engine, no good.

I have 9.8-1 comp 355 with the nitrous 262 cam and Canfield heads, RPM intake 750 VS. 2600 stall and 3.07 gear.

my motor made 292 RWHP @ 5900 and 421 TQ @2100 on the dyno. My car weighs 200 lbs more than your truck and with sticky tires it ran 12.63 @109.

I went with the smaller cam , as was suggested here. Your right the 274 makes power higher, but how much are you really there ?

Well I don't know who built the engine and I don't know what type pistons it has.

I'm just looking for about 400 flywheel power from this engine. Right now it makes 275 if I'm lucky.

ttt

I'd run a good old CC 268HE or Crane 272/272 Energizer and be done with it!! (A smaller cam like Mike's talking about)...

And don't worry about heads b/c both cams will still rpm above 6,000 rpm anyway with what you have...

Or pick up an old set of medium valved double-humpers and up your CR. to about 10 to 1 and really start to rock with either of the two cam's I mentioned...

Your light weight alone will go a long way helping you against the ricers and ponys if you get her to hook using no more then a cheap set of "slappers" and say about G-60 sized real slicks, imho....

pdq67

So what's special about a smaller cam? Torque?

Don't heads have some affect on rpm range?

It's not just off the line power but power to really haul while cruising along at 40 mph.

After having an LS1 Camaro pull around me and walk off while doing 60 mph has me searching for more power....and I even had a good head start! redface.gif

Well it sounds to me like that Camaro had some work done. And he probably had a T56 to help him out. Even those 4L60s are pretty good. Think about it....even if that Camaro was automatic, it's a 4 speed. Your TH350 with a 3K stall isn't going to keep up with that car from 60mph and quicker. I'm assuming here that you were driving then he pulled up and you 2 went at it. If you guys went at it from a stop, well then you'd have him on take off, but he'd start creeping up on you, and eventually pass you up in the long run.
Just remember one thing, these guys here aren't trying to burst your bubble in search of more hp. I know I felt that way a while back. I was thinking, HUGE cam, really high stall, gears, etc., and I was gonna rock!!! But I was told time and again, that wasn't what I needed. I actually got a little PO'd there for a while thinking the techs I was talking to were trying to tell me what to do. They obviously weren't. They were trying to educate me and show me that bigger isn't always better. A lot of times going smaller is where it's at. Just like a turbo for example. You will NOT benefit from the hugest turbo you can find for a small motor that isn't built for it. Well, just in the same fashion, a bigger cam isn't going to benefit your motor if it's not built for it. I know you did mention you talked to Comp Cams, but just like a doctor, don't go with the first one you hear of. You've still gotta call around, talk to different people (which you are doing by asking questions here), and do your homework.
Coming from a, "I just got beat" stand point, I feel your pain. I remember the first time I lost a street race, a couple years back, I was really devistated. But hey, you bounce back from it and move on. You look to improve your car's performance and do it the right way, not by slapping whatever comes your way, or is sold by the "bigger is better" moto. As for you asking what's so special about a smaller cam, I can't explain in precise detail the answer of that, and I wouldn't want to try and totally miss the mark, so I'll let someone else chime in.

well, i'm going to make another suggestion and see if others agree with me.

I believe the action plus is similar to the performer int., which makes advertised power from 1000 to 5000, that might not be efficient for what your wanting. I would also think you could use the 750 carb, it'll make just a little more HP above the 3K where your converter is.

Now the bad news as i see it, I only make 370 FLWHP and i have a far superior head than you do. I don't think your going to reach that 400 FLHP # with those heads, unless the rest of the combo is really radical.

I would just step up the intake and larger carb first of all.

Do you already have the XE 274 ? If yes advance it 4 deg, if not get the 268.

I hope i helped and others will check my info and agree or dis agree.

Mike

The action plus is rated at idle to 6000 rpm. The performer is rated at idle to 5500 rpm.

No I don't have the cam yet. I'm in the process of getting ideas and seeing if the experts here agree or not before purchasing parts.

Yeah I guess you're right...the fact that Camaro had at least another gear on me helped him stay within his power range. I couldn't tell you if it was modded or not. All I know is at the light he was behind me....light turns green...I take off kinda hard (didn't squeal tires or anything) and I'm mid point into the throttle when I see him coming so I give it a bit more gas but then he comes around me and goes off.

I agree most here are tring to help. But sometimes it does get frustrating. In a way I kinda think it's their way of telling us to slow down we don't need to go fast. smile.gif