Any Suggestions

[1971droptop]

I almost put this in the 5.7 in an e-body thread but I thought I could get more attention with a new one. My story is I put in a crate 5.7 in my 71 Challenger and it's not what I thought it would be, it seems to run rich and doesn't feel any stronger than my stock 340 was. I have a Magnum with the 5.7 and it flies. I'm assuming mostly because of the tranny match and rear end. I have a 727 auto with a 3:55 posi. Anyway the suggestions that I'm looking for is how to increase the power without breaking the bank. I don't know how deep I'd like to go into a brand new engine but I'm keeping an open mind. Alright mopar lovers let's hear what ya got!

[whitesatinmopar]

I've seen and heard some guys here talk about the "update", of the new hemi's in old Mopars. Appears a few have worked out fine, but seems the one you chose (5.7) is rated the lower performer of the two. As you stated the tranny/rearend is key. And I will admit they look sharp, saw Mark's (Confederate Cuda) at Carlisle, that is just simply beautiful.  But personally, I'd take the money and buy a street 426 Hemi first anyday, and I'd find an old block as opposed to a new crate engine. I also have heard some negative things about them as well. Not "throwing stones" here, just sharing my personal view as well as what I've read and heard. Good Luck, certainly there are more than a few guys here who can help you with your questions. 

[quapman]

Is there any tunability in the computer?

Disregard if you're running a carb.

[torredcuda]

Carb or injection?Sounds like you may have tuning issues.I have a 5.7 in my 3/4 ton truck and although I haven`t taken it down the track yet it moves out pretty good for a very heavy vehicle.Air intake, computer tuning and such will increase performance also.

[Road_Runner]

Aren't these rated around 350 hp with a carb?  If so, you're 340 probably did perform about the same.  Unfortunately, it seems that the whole computer control thing is necessary for modern day Vettes, Camaros, etc. to run like they do with 'relatively' small motors.  Both cars small blocks put out more hp then most/all big blocks did back in the day.  Maybe not torque though since that seems to favor large cubic inches.  Good luck with yours, I'd love to see some pics.

Later, Jim