Changing a 4.6 Mod Motor for 5.0 (or 5.8)?

ImportEater98

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Mar 17, 2003
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Worcester, MA
Hopefully i am not off topic but this is the closest forum in regards to my question. I have a 1998 GT with the 4.6 2V. I am fed up with the overpriced aftermarket heads, cams, etc. I feel like i could take that money and build a pretty nice pushrod engine. The car is equipped with the T-45 5-speed, 8.8 rearend. How much work am i looking at? I want to build an engine with about 400 flywheel hp/450 flywheel ftlbs/torque. Should i stick with EFI or run carburated? Emissions/inspection sticker is no problem i got a friend. Any suggestions would be great! Thanks
John
 
ImportEater98 said:
Hopefully i am not off topic but this is the closest forum in regards to my question. I have a 1998 GT with the 4.6 2V. I am fed up with the overpriced aftermarket heads, cams, etc. I feel like i could take that money and build a pretty nice pushrod engine. The car is equipped with the T-45 5-speed, 8.8 rearend. How much work am i looking at? I want to build an engine with about 400 flywheel hp/450 flywheel ftlbs/torque. Should i stick with EFI or run carburated? Emissions/inspection sticker is no problem i got a friend. Any suggestions would be great! Thanks
John
With my 96, I figured it would have cost about $3,000 to do a PI headswap "right" and that would have put me at just a little better than a stock 99+ -- not good enough. :bang:

I finally said, "this is nuts". The next week I found a 95 black VERT for $7k with new top, kick-ass stereo, 3.73s, 4" cowl hood, Weld draglites, shorty headers, and CAI. AND it was only 10 minutes away, so I'm like, "I'm supposed to have this car!". I jumped and bought it. It is getting ported E7 heads and a TFS intake installed right now. I also got control arms, pulleys, lowering springs, TwEECer RT, and a laptop. :nice:

Damn, $3000 goes a whole lot farther on a 5.0 than it does on a 4.6. :banana:

In a few years, when the engine starts getting tired, I'm going to drop in a CHP 347 stroker.
 
ImportEater98 said:
Hopefully i am not off topic but this is the closest forum in regards to my question. I have a 1998 GT with the 4.6 2V. I am fed up with the overpriced aftermarket heads, cams, etc. I feel like i could take that money and build a pretty nice pushrod engine. The car is equipped with the T-45 5-speed, 8.8 rearend. How much work am i looking at? I want to build an engine with about 400 flywheel hp/450 flywheel ftlbs/torque. Should i stick with EFI or run carburated? Emissions/inspection sticker is no problem i got a friend. Any suggestions would be great! Thanks
John
sorry, i was so busy telling my story that i forgot about your question.

i'm not an expert, but my guess is that the biggest headache will be the computer swap with all the rewiring for the harness. you may be able to use your current sensors and computer, but i bet there are at least a few incompatibilities.
 
Why not a SOHC 5.4? If you are going to go back to a pushrod based motor, you might as well start with a 351 block.

A SOHC 4.6 can run with a streetable 302. What kind of power does a P&P PI headswap, and an aggressive set of cams produce with all the regular bolt-ons on a 4.6? I don't see the sense in taking out the 4.6 motor then buying a whole 5.0 motor and having to change everything to get it to fit. Sure a the heads, cam and intake cost less for a 302, but you are going to make up for that in price by buying a 5.0. You don't even need to buy a new manifold for the 4.6 headswap, right? So you are probably looking at 3500 for a heads and cams swap in a 4.6, right? That is about $500 more than a 5.0 swap.

If you are still set on a pushrod motor I wouldn't even look into a 302 stroker. I just can't justify spending (almost) the same amount of money to build something like a 331, when you can spend the extra ~300 bucks and have a 351, which still has much more potential than a 331. I can tell you now that a 400 horsepower car will not suffice when you know that there is so much more locked inside of it.

Joe
 
I think in your position a carbed 351 would be a good motor to go with. You could probably get away with using your stock harness because it carbed.

But remember. switching to a motor older that your car is illegal. Most states wont allow it. But if you dont have to worry about emissions, forget about it.

Honestly I think you'd be better off going with a 94-95 mustang and go from there. But its up to you.

:OT: Hows the launch with your lakewoods. Ive been eying that combination and Im wondering how streetable it is. I live in chicago so Im stop and go driving all the time. It would be nice to have better traction off the line.
 
Yes I do, Daddy :) And through much thought about it...i think you guys are all right...gotta pick upa 94-95. Why the hell did they switch to the 4.6? Granted it runs a bit cleaner than the 5.0 (No smogpump, etc.), but what a bitch to do anything in. I'm so jealous i met a guy at a stang meet and he had a fox with a 306 in it, and i could actually see AND touch every bolt on each header! Thats a pipedream in the modular world :(
Well thanks for you help guys. I appreciate it.
Daddy......we'll be in touch
 
P.S. Me and Yellow1995Cobra both run lakewoods. Mines not a daily driver, but its very streetable. Its a little hairy on the highway, but that might be because the front swaybar is out. Never had it in when i put the lakewoods in. Definately a big improvement on the weight transfer during launch. Yellow1995Cobra is running much more horsepower than me so he'll know how it works in higher horsepower applications.
Peace