I can't decide. It's going to be my dd and no matter what I'm going to strap a blowzilla/flowzilla on top of either a set of afr smog legal 185's or trick flow smog legal 185's full forged rotating assembly and cam to match. I also want to start at 10 psi and see how she is and then go from there. I don't think I'll go past 14 psi. What do you guys think?
306, 331 or 347
- Thread starter Insayne
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ivan12
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Im guessing stock block? If so I would go 306 or 331. 347 plus 10lbs of KB boost doesn't sound so safe in a stock block unless you get a super conservative tune and don't get on it as much, but then what would be the point of throwing all this time and money at it. Now if your starting with an aftermarket block then 347 all the way.
Any unpleasant things about 347's has been cleared up for at least 10 years. Better parts and better technology as long as you buy from a good source, like Probe/CHP, fordstrokers, etc.
Go 347. You won't have to run 10psi to get the same level of HP as you would w/ a 306. You can get a 28 oz assembly and that will help w/ getting the 20 pounds of dead weight off the snout.
If you plan to run 14 PSI buy the strongest intake you can find because the block isn't going to keep itself together w/o some help (insert LOL here)
Plan on 347, good I beams(h beams if you ever intend to go to a better block) good slightly dished piston, more dish if you can mill the heads down, gets the flame on the piston and out of the chamber.
If you were going aftermarket block those 3 choices shouldn't even come to mind. 363 or nothing.
Go 347. You won't have to run 10psi to get the same level of HP as you would w/ a 306. You can get a 28 oz assembly and that will help w/ getting the 20 pounds of dead weight off the snout.
If you plan to run 14 PSI buy the strongest intake you can find because the block isn't going to keep itself together w/o some help (insert LOL here)
Plan on 347, good I beams(h beams if you ever intend to go to a better block) good slightly dished piston, more dish if you can mill the heads down, gets the flame on the piston and out of the chamber.
If you were going aftermarket block those 3 choices shouldn't even come to mind. 363 or nothing.
Yeah no dice on the aftermarket block as I'm going to building a Windsor based stroker over the next couple years for an ugly 72 mustang coupe I have just sitting. How bad is oil consumption with the 347? And reliability on the street?
Oil use is really only bad on a hand full of kits that have the oil ring completely into the pin, most have it moved to the top edge of the pin and its not anything more than a normal engine. Reliability is going to be determined by the quality of parts you buy and the way its assembled.
hit us back up before you start buying parts and i'll help w/ what i can as well as the assembly and what to watch out for.
hit us back up before you start buying parts and i'll help w/ what i can as well as the assembly and what to watch out for.
Build a 347. The reliability thing is a myth and has been disproved time and time again. I wouldn't even think twice about offset grinding a 3.4" crank to 3.5" making a 357 stroker in an 8.2 block.
people arguing rod/ratio's need to take a look at some of the OEM engines over the past 50 years. Many of them that last 200k miles have "worse" ratio's than a 347.
Have it built by a good shop, and don't worry about it.
people arguing rod/ratio's need to take a look at some of the OEM engines over the past 50 years. Many of them that last 200k miles have "worse" ratio's than a 347.
Have it built by a good shop, and don't worry about it.
modo
Well-Known Member
dont waste money putting a aftermarket rotating assembly in a factory block. just buy the h/c/i slap the blower of choice on and drive the piss out of it.
rz5.0
Legend
thismodo said:
Win
Legend
modo said:
Agreed.
My build is somewhat similar to a old one you did.
I agree with Paul. The only thing I would do different is a 331. If you are planning to stay at about 500 no need for an aftermarket block. To be honest a 306 with a set of good heads and that blower will put you at 500 too.Paul said:
RPM is just as big a killer to the stock block as power output. IMO a 331 will need a little more RPM to match the same output as a 347, and more RPM = better chance of breaking the block. Again, i'd take a 347 with less revs then a 331 at the same power level.
modo
Well-Known Member
power difference between a 4.030" bore 331 vs a 347 is going to be minimal. now make it a 4.125" bore vs a 4.030" and its going to be a lot more of a difference and will be a shorter stroke 
apples to oranges but if a blower is going on with a h/c/i setup it really is pointless to spend the $ for a stroker setup as you won't be able to use it. i cracked 600 with a stock 302 h/c/i and a s-trim and had a hard time taking power out of it to make it live. buy the right parts the first time and enjoy the car.
now if a aftermarket block is concerned the 185s are pointless and i would be looking at a shorter stroke larger bore rotating assembly if a blower / nitrous is involved but thats me
apples to oranges but if a blower is going on with a h/c/i setup it really is pointless to spend the $ for a stroker setup as you won't be able to use it. i cracked 600 with a stock 302 h/c/i and a s-trim and had a hard time taking power out of it to make it live. buy the right parts the first time and enjoy the car.
now if a aftermarket block is concerned the 185s are pointless and i would be looking at a shorter stroke larger bore rotating assembly if a blower / nitrous is involved but thats me
Different strokes for different folks. (pun intended). Everyone has their preference, neither is right or wrong. IMO, shorter strokes are never a plus, but that is just me.
Dart block, bet your A i'd bore it 4.155 or 4.185, score a 3.5" lunati crank and grind it down to a honda rod journal somewhere around 3.7" stroke and go 402 in an 8.2 deck.
But, i'm crazy.
Being that its a stock block blower car I'd keep it a 302/306 just because it saves money by using the 302 stuff. Leaves more coin for heads/cam/intake/blower.
N/A, always take the cubes.
Dart block, bet your A i'd bore it 4.155 or 4.185, score a 3.5" lunati crank and grind it down to a honda rod journal somewhere around 3.7" stroke and go 402 in an 8.2 deck.
But, i'm crazy.
Being that its a stock block blower car I'd keep it a 302/306 just because it saves money by using the 302 stuff. Leaves more coin for heads/cam/intake/blower.
N/A, always take the cubes.
408? Is there room in this discussion for a 408? No need to worry about an aftermarket block with a Windsor!
i think the comment was made that he would be building a windsor down the line but the added cost of supporting mods for a 408 if you already have them for a 8.2 really drives the cost up. he's also in cali so that comes into play too.
if he wasn't looking at emmissions stuff i'd be hollering build a TLSR 347 w/ a spyder intake and afr 225's and make boosted power all motor.
if he wasn't looking at emmissions stuff i'd be hollering build a TLSR 347 w/ a spyder intake and afr 225's and make boosted power all motor.
