Stock manifolds are going to choak any work you do on the heads, and the E7 stock heads are going to choak any cam that you put in. Ford didn't help that 351w at all; choaking it with those low flow stock heads and low flow manifolds it will be hard to pull any more power out of that motor without doing something at least to the exhaust... Allowing more air in and more exhaust out is the basis for all other power upgrades. How much are you willing to put in? Are you doing any of the work yourself???

Trust me when I say rebuilding the E7's isn't worth it! By the time a machine shop cleans, decks, does a valve job... etc... You'll have more in to those E7 than spending $500 on a set of aftermarket ones. Just giving you a heads up...

 

^ No, I'm talking about rebuilding a set of GT40's... Having the shop handle everything.

Rebuilding GT40 heads with a small, small cam on the stock bottem end. Stock EFI parts, intake manifold, etc. As far as exhaust goes: short tubes or stock manifolds, into a Bassani Y-pipe, then a single 3" Magnaflow.

If the motor is opened up, the E7's will be the first to go. Again, Im looking to keep it as close to stock as I can and keep the cost down, while not cutting corners.

 

Putting shorties on instead of Longtubes is cutting a corner I think. If you have teh bassani Y-pipe, you can sell that since they stopped making them and prolly break even on having a new exhaust fabbed up to the Longtubes...just saying...

I will agree that doing all that motor work and then putting the stock manifolds back on is a terrible idea.

 

Sorry man, no long tubes haha.

Here's the thing on the stock manifold... they have 2" collectors if I am not mistaken.If I run the Bassani Y or a "custom" Y with a 3" leg and muffler, are they really a cork? Maybe, but are short tubes worth $200-300 over the manifolds? Hard to say... Sure they will scavenge better but on the low end, I don't see it mattering much.

And to rain on my parade haha, looks like they don't make FRPP short tubes for 5.8 trucks anymore. After I saw that, I was like "maybe the stockers will do."

 

A custom y and 3" all the way back would be good. But aren't the stock manifolds different sizes? Shorties would be good but worth 300...not in my book. Heck I only paid 350 for my LTs and my custom y.

Just seems a waste to do heads and a cam or intake and keep the stock manifolds. Those are usually the first to go.

 

^ Manifolds aren't ideal, for sure and I'm not dead set on using them. They just seem like a viable option.

What do you mean by "different sizes"?

 

I hate to keep raggin on about this but this might make my point clearer... Maybe not... LOL... Let me know...

Ok, same deal... GT40's are still a cast head. They flow 20% better and IF you can get them in good condition ready to strap on for a couple hundred they are worth the upgrade. However, if you have to completely rebuild gt-40s the time and expense would be better spent on a cheap set of aftermarket heads that will flow better than gt40's and be close to the same price as rebuilt gt40's...

Look if you are willing to drop $300 on a set of shorties, why not get a set of pacesetter 70-2221 long tubes. they are right at $300, won't choak the engine and will scavenge better for low end torque. The problem with the stock mani's is that they have smaller exhaust port intakes than the gt-40's exhaust ports. As a rule of thumb you want to be as big or slightly larger as the gas flows out. Plus the stock mani's have don't have a smooth flow to them to allow gases out as quick. The rough cast inside might help a intake atomize fuel but it definatly doesn't help exhaust move quickly. Also the sharp turns in the stock manifolds cut down the air flow as well.

All shorties do is smoothe out the exhaust flow to exit the gas quicker.

Let's talk a min about scavenging... scavenging is what results fromt the primary tubes (tubes run from head to collector) being made a particular length, taking into account the time it takes the gas to move out. When the exhaust from one primary passes into the collector it actually makes a little suction that draws the exhaust out of another cylinder that just opened at the head. So you are basicly sucking the gas out of your heads at a faster rate. In some instances this also helps to draw in a denser charge into the cylinder making more power at each cylinder. If shorties add 3-5 rwhp you'll get 15-25 rwhp from long tubes... Of course that is just a example and one that I have commonly read in mustang forums for 5.0L engines. I'm sure the 351w are slightly different in power gains from long tubes.

I'm just trying to educate man... I'd hate to see you spend $300 for 3-5hp when you could be spending the same for $15. Also you might want to let us know what cam your thinking of using and what you're paying for it. RV cams are cheap enough for some extra torque ($100) but you'd have to talk to Paul (Conanski) about cam options. He seems to always hit the nail on the head when someone asks him a cam question.

I said my piece... Let us know what your quote says. Please include part numbers and prices!!!! (helps other in the future)

 

^ Thanks, Steve. I agree with you on most points and have considered the cost of rebuilt GT40's vs new heads as well as manifolds vs. shorties. Again, longtubes are not in the cards regardless of price/cost.

We had a miscommuntication on the quote... the guy was super helpful but gave me a quote for a complete motor rebuild. IMHO, that's not needed. I was looking to leave the short block alone and just have a fresh top end.

Anyways it came out to $4100 to rebuild the heads, pull the motor and rebuild it(hone the block, new bearings, rings, gaskets, water pump, etc) buy + install a FRPP B cam(just his example, I have no interest in using one) and do exhaust work.

Your thoughts? The truck has 165K miles on it... The stock bottom end should be good for 100+K miles as is. IMHO, I could leave the bottem end alone and go with heads,a small cam, exhaust and be done... That should net me a strong small block that is 100% drivable, efficient and emissions compliant. Or is that cutting corners haha?

 

It's possible that location has something to do with the price, but $4,100 seems very high for the stated work, especially as it does not include machine work to the crank, block, etc.

If I were to spend that kinda money I'd have the sucker machined within an inch of its life. Align bored (crank and cam), decked, turned, deburred, chamfered, balanced, resized, and the list goes on.

$4,100 is just crazy for a re-ring, valve lap and new exhaust.

 

I got a buddy, he paid $4800 for a 383 stroker.

 

^ Considering parts and labor, the price seems fair... I just wasn't looking to commit that much into it. It a 15 year old truck, I am not looking to prove any points with it haha, just enjoy it.

 

The plan sounds good to me to freshen up the motor and grab a few extra HP while ur at it...

I obviously don't know your personal situation, how old you are, or how much disposable time you have but...

Considering I can get a set of heads rebuilt at my machine shop for $500-600ish, cam/timing set/lifter set for $200ish, water pump $40... and exhaust is an x-factor...

Lets add in a little cushion and say $1000 for all that work if I did it myself less the exhaust... I'm just saying it's easy enough to find some gt40s get them rebuilt and do a head and cam swap on the weekend to save a buck. I'd probably take it to a shop for exhaust too...

So are you thinking entire rebuild now with the $4100 price or just having them do the heads and cam?

PS: you should clean the injectors or get new ones at 165K when you do all of this...

 

^ I don't feel comfortable enough to tear into the motor alone. I may get a quote for just the heads/cam install + exhaust, but at $4100, I am not interested in a full rebuild at this point in time. The Mustang is my DD so downtime wouldn't be an issue.

I'm still interested in a mild 351 in truck, I may have to get more creative, or learn to do motor work.

 

A good Chiltons book, a case of beer, an a couple old timers.....A Full rebuild kit is roughly $5-700 depending......Just saying......

 

That Bassani Y-pipe is going to cost you a fortune if you didn't get one back when the dot coms had them at blow out pricing. Just not worth it in my book. More so on the 5.8. Most are not 2 into one, till the cat. On a 5.0 I get it... It would be more cost effective to make it true duel.