Thinking of building a new engine for my 95 GT

[302hobronco]

It's easy to go down the rabbit hole of changing one thing that requires you to change another thing and another thing. That's why I like the explorer parts, there stock so you know they are going to work. And they will increase power.
Just keep it simple, mild cam, better heads and better intake. Easy peize.

 

[castine917]

With the added criteria of convertible brace, I now suggest 331/347 stroker. I also forgot your stock manifold criteria. Stock 351 manifolds could have been used as a gray area of keeping with that compliance. The added torque from the added cubes is going to be of greater benefit to your 3000 rpm driving than most other mods.

Stock ecu could control 351 or 331/347 stroker with a tune. With most any mods you would want a tune anyway. The 351 could fit under a stock hood and a stock brace but your intake being a lower profile carb style lower with an elbow would be best for clearance.

 

[r1ch999999]

There is a Cobra convertible stb that should help clear things. I've been on the lookout for one.

 

[maillemaker]

I could also just drop a 94/95 Cobra engine in here, I guess. So that would need a different cross brace for the convertible? Does anyone make an aftermarket one? Would I need a Cobra ECM to drive it, or would my ECM drive it?

 

[Wood's 5.0]

@RAU03MACH
Man, diggin' that Motorsport GT-40 intake cover!
I looked and looked for one for mine but never could find one someone was willing to sell.

 

[RAU03MACH]

there is a guy on ebay that makes them
and he will stamp them with ford racing, motorsports, gt40, lightning, and mustang
and sells them 80 to 90 bucks

 

[itsell]

Sure are a lot of people in this thread with little to no understanding of the octane requirements of an engine. If you build an engine with near the stock compression ratio, it will run just fine on 87 octane. Higher octane gas is not “better”, it simply has more octane to avoid knock in engines with higher compression.
If the OP were to build a stock bottom end 5.0 with say Ford Performance X2 64CC chamber heads, the compression would be the same as with E7TE stock heads which also have 64CC chambers give or take. it would run on 87 octane most likely and make way more power than stock.

So with that being said my recommendation to OP is this.
-Ford Performance X2 street heads with the 64CC chambers.
-a gt40/Cobra intake or equivalent.
-24lb injectors
-75MM mass air tuned for 24lb injectors
-65MM or 70MM throttle body
-Use your stock headers like you said you want to, they’ll be a bit of a restriction but whatever.
-you said you barely rev your engine past 3K, so don’t swap the cam. Keep the stock cam which with run perfectly, not require a tune, and works better than any aftermarket cam in that RPM range. You could use 1.7 rockers with the stock cam to get a little more lift, which you’ll benefit from with the increased flow of everything else.

 

[maillemaker]

Sure are a lot of people in this thread with little to no understanding of the octane requirements of an engine. If you build an engine with near the stock compression ratio, it will run just fine on 87 octane. Higher octane gas is not “better”, it simply has more octane to avoid knock in engines with higher compression.
If the OP were to build a stock bottom end 5.0 with say Ford Performance X2 64CC chamber heads, the compression would be the same as with E7TE stock heads which also have 64CC chambers give or take. it would run on 87 octane most likely and make way more power than stock.

So with that being said my recommendation to OP is this.
-Ford Performance X2 street heads with the 64CC chambers.
-a gt40/Cobra intake or equivalent.
-24lb injectors
-75MM mass air tuned for 24lb injectors
-65MM or 70MM throttle body
-Use your stock headers like you said you want to, they’ll be a bit of a restriction but whatever.
-you said you barely rev your engine past 3K, so don’t swap the cam. Keep the stock cam which with run perfectly, not require a tune, and works better than any aftermarket cam in that RPM range. You could use 1.7 rockers with the stock cam to get a little more lift, which you’ll benefit from with the increased flow of everything else.

Thanks for the info. That was my understanding of compression also.

Are there any headers that are direct bolt-on replacements? I don't want to have to re-do the exhaust.

 

[maillemaker]

Just watched this video on the cost of a mild HCI upgrade:

You're looking at $3500 without even touching the bottom end.

Watching a lot of the Richard Holdener videos with his dyno results usually shows performance gains really take off over 4000 RPM. But the curves are pretty much the same below 3000.

I don't think I'm going to get any real bang for the buck the way I drive around town. If I really wanted increased pep up to 3000 RPM probably a rear end gear swap would give more perceived "go".

At this point I'm thinking a remanufacutred long block from Oreilley's or someplace for $2500 is probably the smart way to go.

 

[itsell]

you’re correct there’s nothing wrong with the factory setup for street driving. That’s what it was designed for, low end torque from idle on, and all the power before 5k rpm. People that do top end rebuilds are generally are looking for more power higher in the rpm range.

You could do a rebuild that would behave just like the factory engine’s power curve, only more so. Something involving the factory cam, or an aftermarket cam with similar characteristics, with the better heads, like I was describing above. It’s just a matter of whether it’s worth it to you or not, and it sound like probably not.

To be clear about Richard Holdener’s usual builds, he’s usually using a high duration cam made to operate in the higher rpm range, like 3k rpm and beyond, hence the power below 3k rpm being nearly the same as stock. If you were to shove in a performance cam designed to operate from idle, similar to the stock cam, then it would make more in the idle to 3k rpm with the better heads, intake, ect. It’s all about the cam’s functional rpm range.

 

[castine917]

Thanks for the info. That was my understanding of compression also.

Are there any headers that are direct bolt-on replacements? I don't want to have to re-do the exhaust.

Almost all shorty headers are a direct bolt-on replacement. Longtube would require a reconfiguration of your exhaust.

 

[castine917]

I could also just drop a 94/95 Cobra engine in here, I guess. So that would need a different cross brace for the convertible? Does anyone make an aftermarket one? Would I need a Cobra ECM to drive it, or would my ECM drive it?

Your ECM could be used but, would benefit from a tune. Especially if you switch from the 19lb GT injector to the 24lb Cobra injector.

 

[Daryl]

Not to be a Killjoy, but if it’s an A to B car, never over 3000rpm, why are you building a motor like that? You could do a stock rebuild and run like that for another 200k.

Now don’t get me wrong, I’m all in favor of each person doing their own thing because it’s no one’s business but their own , but ….. sounds like you’re over-doing it for its attended use. Just my unsolicited $.02

 

[maillemaker]

Not to be a Killjoy, but if it’s an A to B car, never over 3000rpm, why are you building a motor like that? You could do a stock rebuild and run like that for another 200k.

Now don’t get me wrong, I’m all in favor of each person doing their own thing because it’s no one’s business but their own , but ….. sounds like you’re over-doing it for its attended use. Just my unsolicited $.02

See Post #49.

 

[Daryl]

See Post #49.

Gotcha. My bad. Didn’t scroll up

 

[joemomma]

If you're still on stock gearing, an upgrade there will definitely be the best thing you can do. Then add a stock replacement block and you're golden for your intended purpose.

 

[maillemaker]

Gotcha. My bad. Didn’t scroll up

Yes, it's 3 pages of me slowly coming to my senses.

 

[Randall Garner]

Fitment of a 351w under the stock hood is a good question. Vert motor mounts are supposedly lower than coupe mounts. Plus to fit under the hood, I've seen the stock 351w efi lower intake ported to fit the stock 302 upper intake. It isn't pretty, but can work. I doubt the strut brace will clear. Also, you will need a 351w oil pan and pick up that fits fox body platform.

If you have the efi carb type intake and a good carb looking throttle body . You can keep things low enough if you look for a 95-96 truck 351 things will be easier in cost . A 351 is about 2" taller, and nearly 3" wider overall . And a 351 swap oil pan, oil pickup. 302 header will work but maybe tight against the floor .