I am going to buy a GM crate motor for my knock-around truck. I am looking at both the 260 and 290 HP versions of the generic 350. They both appear to be the same engine, except for cams. I like the extra 30 horses of the 290 HP version, but I hate to lose 24 FP of torque (326 FP vs 350 FP) of the higher HP engine.

For those of you who know cams: I think I can do better by purchasing the cheaper version of the motor and using an aftermarket cam in it. I want to stay with a cam that is totally for the street, and can use 87 or 89 octane fuel. It will do some medium-duty towing and be a daily driver. It is a 1986 model truck, with no computer, a TH350 Transmission with a lock-up converter, and a 3.42 gear. I would like to raise torque more than horsepower, and would see no reason to ever need more than, say, 5500 RPM.

Any thoughts?

Thanks,
Mike

I don't know that it's the best choice but I have the generic 204/214 @ .050 cam (Performer Plus type). I tow my bracket car with it in my 66 Elky. It likes 1.6 rocker. In my car with 3.36 gears it pulls strong to 5500.

Pat,
That rocker arm ratio was a part of my question I forgot to ask. I wondered if using a 1.6 ratio on the stock cam would result in anything significant. It sounds like your cam is in the ball park of the CompCams 260HE, which I was looking at.

Thanks,
Mike

I have that "Hecho en Mexico" generic 260 horse GM crate in one of my cars. 650 DP Holley, Performer, 1 5/8" headers, 2 1/2" dual exhausts and a recurved HEI. It has the stock cam.

It runs great even with 3.08 gears and a stock converter BUT it is ALL DONE at 4900 rpms. It is decent on gas after I tuned the hell out of it.

Randy

You have to remember that the Goodwrench 350 motor is only about 8 to 1 CR. so don't over cam it!! Pat is right in there with his suggestion imho.

Maybe Travis from generally over at "Little Brother's" site, (Team Camaro), will chime in here b/c he really is into what you are talking about big-time!!

Might look for him over there b/c he recently posted a bunch of good info in a thread like this..

pdq67

The 260 HE might be a better choice. It has shorter seat times (260 vs 278) and a tighter LSA (110 vs 112) which will increase cylinder pressure for more bottom end torque. With the 8.5, or less, CR of the crate, I doubt you'd need anything more than 89 octane, if that.

I have 1.6's on both the intake and exhaust but, and I haven't tested this with this engine, they usually make more power with them only on the intakes. At least on race/HiPo engines.

I've never ran 1.6's on a stock cam (haven't had a stock cam since I don't know when) so I can't say how much they would help. I'm sure they wouldn't hurt. And even if they don't do much, they should with an aftermarket cam if you go that way. The extra lift will help build torque.

i was also thinking about doing the same thing that you are with these two engines. I read that the 290hp version was dynoed with 1 3/4" dyno headers which may account for the lower torque output while the 260hp version was tested with 1 5/8" headers. The 290hp cam specs are .450/.460 lift and 222@.050 duration on 114 centerline. I believe this was the L-82/L-46 cam used in some performance 350's. I would think either of these motors would benefit from a modern short duration cam profile. I am considering one of the smaller voodoo cams. There is one thing that I don't understand about these engines. The 260hp is listed at 8.5 to 1 and the 290hp is listed at 8.0 to 1? Both engnes are listed as having the same exact parts (with the exception of the cam). So I'm not sure why the compression ratios are different.

Thanks for the additional info 69bu. I don't know what to make of the CR difference either. I wonder if the larger headers make the difference in torque, and what the HP would be if they had used the smaller headers on the 290 version?? What do you like about the Voodo cam vs the competition?

Thanks,
Mike

I think the larger tubes would defintely affect torque output, but I don't think that they would have added much more horsepower because this motor can't really take advantage of the larger headers. As far as cam preference, I have just heard alot of good info. on this board about the voodoo. Granted most of this heresay, I am not sure if anyone here is actually running one yet. I had been wanting to try a Lunati camshaft for a while. I have used mostly Crane in the past and just wanted to try something different. Hopefully I will get to try one out in the next couple of months.