[glhs#116]

Originally Posted by HO Kenny

Sam, it sounds like your car is similar to mine. It pulls right up to aprox. 5300
rpm when the tranny shifts. It drops off after 5300 but, it did that with the 068 cam. It has no pinging problems; however, we live at 3500 ft. The air is thin here. It has the xe 268. I think it could handle the xe 274.
I had a 350 pontiac with about 11:1 and an older version of the xe268. It would pull to 6000 in top gear not a problem and thats with 3.31 rear gears. I shifted it at about 5400 rpm to keep it in the tq. curve. It did have pinging problems in the lower rpm band.
Did you know that the 71 & 72 ho engines had special lifters (high ball or low ball I can't remember)? I've heard that they would pump up to keep us from over reving our engines.
ken

Wow! You don't say!

You know, I was doing a bit of a run from a stop to evaluate my fuel supply problems. It seems to be heat related. In top gear in the daytime (hellishly hot) I start to cut out under full throttle. In top gear at night (only heckishly hot) I pull pretty firmly at WOT to over 5000rpm in top. So, I was trying a non-burning but heavy start in 1 and manually shifting the TH350 at WOT. I found that clicking to 2 didn't shift immediately and the engine went higher than I intended. Heard a lot of thrashing and it dropped dead. Came back to life in second (without my foot moving). I swear, the first thing I thought when I heard that noise was "valve float". I was thinking maybe the lifters were worn but now I'm thinking maybe that's just what they were designed to do.

Fuel starvation still sucks! I'm going to try some ways to insulate my lines better. I'm thinking slitting a rubber line and wrapping it around the metal one where it is close to engine/manifolds...

Sam

[JohnnyC]

I see nobody has mentioned the raiv cam, or really a variation(unless I missed something). This made me wonder, because I have researched many other posts in which people have recommneded it as a great cam in a 455+ cube engine. Have some of you(hardcore enthusiasts/researchers) changed your mind on this opinion? The reason I'm really wondering is because I have a similiar set up to ta-kid, and like him,, have been really struggling, researching, and coming up confused about the right cam for my car. So many choices, and even more opinions. Thanks

[speedshopmike]

ra4 cam would like a higher compression ratio

[Brandi Kay]

I got the XE268 in my 455.

i originally wanted the XE274, but after talking to Ken, we agreed on the XE268.

The combonation of the Pdude455, street port heads, 268 and 800 holley and tremec tko 600 is SICK A$S MUI%^ERTrucking power!!!!!!

no traction in first 3 gears at any rpm when you have more then 1/4 throttle.

someone said a 455 with a non posi is like driving on ice, they are right.

mines a daily driver, so the 268 is a great combo for street, strip and not terrible gas mileage. (it uses more then my 350, but i knew it would and im not complaining.)


if yours is a DAILY driver, go with the 268, if its a weekend warrior, go with the 274.

[Brandi Kay]

and unless you got slicks (with a POSI), the 268 WONT hook anywhere with a 455! Dont underestimate the power of the force.

its sick power, ive never experienced anything like it.

[runningbwdog]

Hi Brandi,
Sounds like you need dough rollers on the back of your car.
During the last two weeks of my High School Exchange Student's stay with us, I taught her how to drive a manual transmission car. Up to that time she chauffered me around in my automatic Silverado. The only stick car I own is my 68 GTO with an XE 268.
This is how it proceeded: I told her to let off the clutch very slowly, don't touch the gas. The car will start rolling. Once the clutch was fully released and her foot was off the pedal, she could add some throttle pressure. Needless to say, on her first attempt she applied way too much throttle pressure. What a hoot to see her reaction!!!!!
She panicked and slammed on the brakes. The car is equipped with very good power brakes. After we scraped ourselves off the dashboard. We tried again.
For her second try, I told her to do the same thing, but this time press on the throttle like there was an egg between her foot and the pedal. Much better the second time. After that I taught her how to shift up and down based on the speed of the car and anticipated maneuvers.
Obviously, she won't be driving a car with as much power as my GTO in Germany.
When I took her to the airport to go home, she said that driving the GTO was one of her most memorable experiences while she was in the USA.
Mike