I know this is a very general question, but assuming you don't cut costs on either one, which of the two will be cheaper and put out more power? What factors should be taken into consideration when deciding between the two different types of motors?
if its N/A then its plain simple "there is NO replacement for displacement." the 408, well built, will be the preverbial stump puller...or a literal one if you like. the 347 would be a good high rpm FI motor.
exactly what he said, for NA the 408 will make more power all else being equal, but the 347 can be built much cheaper and if you have a power adder it really may not matter too much anyways plus you save the weight with the aluminum block.
Then you can always factor in the 370 which is a 408 sing a stock size crank or stock crank.
There is also a All bore 388 which is a great motor to turn some serious RPM while keeping the weight down.
I know you only asked for the 347 vs 408 comparision, just thought I would bring up a couple different combo's.
In my oponion the 408 is bad ***, and well worth the extra money. You can run a large cam without haveing the normal large cam issue's and the car will drive more like stock until you hit the gas pedal.
What kind of setup are you thinking about doing.
Well, budget IS a big factor. Setting cash aside, other than mpg, most people will not see much downside to bigger cubes and the upside is a lot of torque & HP. If you have a very specific plan or goal, you need to post it up.
__________________ 2008 Atomic Orange Coupe 3LT, CC3, Z51 M6
LG Pros with cats, Vararam, 160 T-stat, DTE 3.90s, Elite tunnel plate, Pfadt JOC Stage I, catch can, LG Wheels with 275 / 325 Invos MGW Shifter, EPS 226/230 115 cam, Peak ported IM & TB, HPT.
Gone but not forgotten:
2002 Camaro SS Droptop. cam, gears, etc.
11 sec 99 Z28 Vert, RIP.
Quick overview of my goals/use of the car........looking to have it streetable (driven a few days out of the week in the summer) and make as much power as possible without being a high maintainence car. Will see several track trips per season, but my main concern is going fast on the street while being behind a 6 spd trans. FI is out of the question, N/A and nitrous only.