this is what im looking at for my 351w topend

thank you and i know your not knocking my 351 so its all good

 

ooh and the bottom end is not finshed

 

Let's take a look at this with an analytical approach;

347 stroker
PROs

1. Lightweight and quick reving
2. About 80lbs lighter
3. Improved components over stock 302 (H beam rods, good crank/pistons)
Same dimensions as stock 302, don't have to worry about headers,
brackets etc., and in the Maverick you don't have to shave the towers
because it is 2" narrower.
4. If built correctly it should yield about 50/70lb.ft. more than stock 302

CONs
1. The 302 block is not as rigid as a 351 block maybe with the exception of
a Mexican block, but those are expensive and hard to find.
2. This will probably get some people that disagree but I would say a well
put together 347 is good for 450hp..........reliably for the street.
3. A 347 is a high revving motor, but for reliabilty I wouldn't go much over
6500 on a regular basis..........beyond that the block flexing can cause a
problem with reliability.
4. Growth as far as HP is minimal unless you use a supercharger or turbo, then
the reliability goes out the window without more internal mod's.

351W with or without stroker
PROs

1. In original form the 351 block is more ridgid. 71 to 74 blocks have about
10lbs more material in the web area than 75 and newer. (You can put 4 bolt
mains on a stock 71/74 block with no issues). They have larger main cap bolts
and rod bolts.
2. You can upgrade performance and push the 351 out ot 427ci without much
of an issue.
3. Taller deck means more torque capability.
4. Stock block will easily handle 550hp if put together right.

CONs

1. 80lbs heavier than the 302/347
2. For the Maverick it does make a very tight fit.
3. To make it fit properly it really requires shaving the towers or if you want to
spend A LOT of money you can ditch the towers and go with an aftermarket
setup.
4. With more torque you need to rebuild the stock trans and modify the 8" to
handle the power or go with a 9" or 8.8.

Let me say, that for the strip, cubic inches make cubic torque, and cubic torque
gets you to the finish line first.
But for the street reliability is key unless you have $100 dollar bills falling out of
your pocket................but on the other hand.............how many street 347's do you see making over 1000hp....................
Just some food for thought.....................................IMHO

 

wow you just answered all of my questions on the rear end and i was tinking of a
4 speed over the 5 speed wha do you think ans a good clutch to go w/

 

Manual trans behind a well built motor say bye bye to the 8" rear!

 

I ran the Edelbrock top end kit, only mine had the roller cam. The Edelbrock cam was the weak point. Very lazy lobe ramps so as to not play havoc with the marginal valve springs that come on the heads. Edelbrock uses a "fits all" spring to work with their flat tappet or roller cams. Kept the heads, intake, etc but changed to a Comp cam. The difference was like night and day.

 

I agree with everything but I question why you made this statement. Just curious. The way I look at it the engine is only as "high revving" as the camshaft specs dictate (the rpm range). I totally agree when you said it's quick revving".

All I was really trying to get across with my first post is that if you built both motors with the same compression ratio, heads, cam, intake manifold type, carb, etc... then the 347 will be the winner in a race every time despite the slightly less cubic inches.

Yes the 351 will be quicker if you're going to build a 408 or 427 stroker.

For a maverick though, the 347 would be a better choice unless you don't mind the aggrevation involved with making them fit (the exhaust).

That being said, there have been plenty of guys who've put 351's in their mavericks and have been very happy.

It's all personal choice and to each thier own. There's more than one way to skin a cat!

Good discussion! :Handshake

 

I have to agree that the 8" will not survive long with a 4/5spd unless you drive with a "raw egg" between your foot and gas pedal.
For a street car unsprung weight is the enemy, so with that info I'd look into other alternatives.
As for a clutch set up, any of the good vendors out there can do it, but a diaphram is the easiest on the street, not the old "Borg&Beck" type.
My Maverick now has a Powerglide, but the clutch pedal is still there...go figure.
I know you are a young guy and 4/5spds are the in thing, but I just prefer auto's, maybe because I am tired of shifting..........it's a pain!
The more and more I look at this "top end kit"..........My Own Opinion.....I would buy each piece by itself...........what I mean is that you can taylor each component to suit your needs...............your motor is very specific to you, and what works for you may not work for the next guy...........etc.
I'd shop around for the heads.........I am partial to TFS...........or maybe AFR and get the right springs, retainers, keepers, chamber size, vavle diameter for your needs....................there is very seldom a "One size fits all", kind of like torque converters....................anyway...........Just My Opinion on this whole thread.................I certainly don't want to offend anyone here on the forum.........because I really like being here..........and I'm sure most everyone on this forum have built motors for the street or racing, and asking everyones opinion is great, but just like going to an AA meeting, you listen to what everyone has to say and take away what you think will work for you. Building a motor is a very personal thing to me, I listen to what everyone has have to say, both experts and the novice group..............but in the end I draw from my own personal experience............building motors is kind of like "belly buttons", everyone has one, but no two are exactly alike.
Again, this is just My Humble Opinion

 

First of all, great post; pros/cons well articulated!

1. 80lbs heavier than the 302/347

An aluminum block pretty much cancels the weight difference, no?

 

man you have so time on you i thank you for your Humble Opinions

 

When you talk about use on the street, wouldn't that mean street tires? Would the 8" be all that vulernable even with street tires?

 

Hi John,

Let me go a little further into the 347 vs 351. I have to say that I would have never gone with a 347 stroker motor on my own, but a friend has asked me to build a motor for his 67 Cougar..............and he wants something with good driveabilty and HP..................hence I am looking at the 347 because the motor fits his car perfectly and he doesn't want to go with the 351w anyway.
So, this is what I have come up for a nice 400hp 347 that should work fine for the street.............
Take the 347 stroker and use TF twisted wedge heads with good springs, retainers/keepers and a CR of 10:1, use a hydraulic roller with 224/232
duration #.050 and .545/.565 lift, make some or buy some 1-5/8" long tube headers.............not sure about the intake yet, but will use a 650 Demon I believe it should make around 400hp at 6000rpm and probably around 380ft lbs
at 4500 ( I say this but fully expect the troque curve to be pretty flat above 3500) which is what a stroker is all about............right?
Now for the 351 which we will probably have to go .030 over (which is realistc)
and use the same TF twisted wedge heads and pistons that will give us 10:1CR, but this time will use a little stronger cam to take advantage of the added CI and torque...........probably .575/.595 lift, again not sure of the intake but we'll use a 750 Demon and probably go with 1-3/4" full length headers.......this is just a guess but I would hope about 450Hp at a little less than 5500/5800rpm, but unlike the 347 I will have about 350ft lbs @ 3000rpm and should have around 430ft lbs @ 5000rpm...........now this is just a guess.............

 

Ok guys, this is fun but I need to get working on the Maverick.

PonyExpress,

To save 80lbs I'd have to spend another $4000usd............only worth it in road racing or drag racing............unless you have $4k pocket change.

Now here is my idea of a great drag motor.............just hard to justify the $$$$$$$,

http://www.ebay.com/itm/Aluminum-42...Parts_Accessories&vxp=mtr&hash=item4161ff99c3

 

You mean "Long-style"... But I agree, I run a CenterForce diaphram and it's a whole lot easier on your leg and the firewall. Don't think I would want a manual trans in my daily driver anymore but in my toy I like to "row".

 

Understand the tradeoff, weight for $$$. But we were talking weight reduction. Less weight, more trq; I intend to pay and play.