I'm looking to make around 500 ponys at the wheels in Denver, Colorado-less air up here-

Question is are LT4 heads stock capable of doing this? I had some mild bowl work done and didn't want to spend much more if it's not need, but what are your thoughts.

It's a 388 with the GM 847 cam w/1.6 rr. Most all other bolt ons and gears.

 

with a 100 shot...

 

I'm sure you won't get there with that cam. There are some here who may be close with a 6sp trans but no one running an automatic trans and those heads.

 

I have to admit, this is a post worthy of a quick search before posting it. A quick read will show your goals are way above what stock LT4 heads are capable of.

 

Just playing the numbers game, AT SEA LEVEL you would need to make about 575flywheelHP to net 500rwHP with a manual trans setup. At the elevation of Denver, you are giving up 15% due to air density.... that would mean you would have to have a head that would support the equivalent of about 675flywheelHP.... don't think you'll make it. If you are talking SAE corrected rwHP, you've got a chance, but of course that means you only be putting an uncorrected 425HP to the rear wheels on the streets of Denver.

 

Fred,

Keep in mind he's talking about LT4 heads with no real porting work. I don't think even 425 RWHP is possible with heads like that.

 

I wasn't too sure what he meant by "LT4 heads stock". Agree.... a good set of 300+cfm worked factory LT4's would be hard pressed to make that kind of HP. A truely "stock" set of LT4's and the 847 wouldn't have a snowballs' chance in hell of coming close.

 

This should be discussed in LT1 Engine Tech- transfering.
Thank you.

 

I forgot about that search button, I apologize.

I think the verdict is in, further head work is needed, matched with a cam.

Thanks for the input, this forum has been very helpful!!

 

I lost 19% hp to the wheels going from Tacoma, WA. to Albuquerque, NM. That's a healthy 56hp and 64 lb. ft. of torque. Went from 296 to 240 at the wheels.