NA 351 or S/C 302?

[Chads95GT]

Hey guys i know this prolly has been asked a 1000 times, but i cant decide which one i want to go with, and i dont have the money to change things if i dont like my choice. ok i have a 95 gt vert 5speed and my current motor is in need of a rebuild. i have roughly 6 grand to spend. so here is my question. would you buy a gt40p motor from a junkyard and supercharge it or build a 351? i have a 351 roller block so thats a plus for that. but this is what i want. i was a decently fast street car(12's would be nice), it will be street driven, it will never see a track and it needs to be reliable enough to take a long road trip. so those who have done the 351 swap: would u do it again or supercharge the 302? which choice will have the more headaches on trying to get the bugs worked out? im able to do the work myself so thats another plus.

thanks for the help,
chad

Oh and are they any of you guys located around Indiana, PA? if so, who do u go to to get your cars tuned?

 

[parchisi]

I would definitely do my 408 (351) swap again. Its a little more money but its worth it. Now whether I'd supercharge it again.......that's a different story.

 

[Pokageek]

"motor is in need of a rebuild"

Well..either way it is certain you will need a new bottom end to do it right if you are going 302. SO I would be pulling the motor either way. Personally? Even after all my pia with my swap I still like the bigger motors. The 351 is cool itself because you dont see alot of them. You can easily run 12's na with one of those and you get the benefit of the stronger block! Later you can go 393 or 408! I just think it is cool to say 351 but you could do the others as well.

If I stayed 302 I would go turbo. It's different and you can get more HP out of it and not need a big cam so it can idle like stock. U have to be careful about going too muchPSI in either case. Sure there's dudes out there with tons of HP but they are going to split the block one day. Do it smart.

 

[Venom351R]

I can speak from experience. I supercharged my last 302 and was putting out about 340 RWHP. Currently I have a 351W in my Cobra that is putting out the same power. Both motors could have or do have room to grow. Putting down numbers at the track N/A feels much more accomplishing then when I was w/ Boost. Ive run down cars last summer that were pushing boost while I was N/A and its just an awesome feeling knowing you can take them down. As much as I like boost Im going ot keep this one N/A for awhile. Plus the TQ on the bigger motors just makes you do this

 

[Black95GTS]

I think the key work being reliable, and running 12s, and going for long distances, I think a 408 with full accessories would be pretty ideal. There's enough juice there to power all your creature comforts and 12s are a breeze. Honestly its easy to take a 302 into the 12s too, but with the 408 you won't have to rev it high at all and you have a ton of options.

A 408 with AFR 205s, a mild cam, and a Victor 5.8 will retain all your creature comforts, EFI, won't need to get much past 6000 RPMs, and should go all day and night.

Don't forget though, you'll need a transmission, rear end, and axles. There's a couple grand. Selling your old 302 parts could help soften the blow.

Just my two cents.

Adam

 

[Chads95GT]

seems like you guys all like the bigger motor. i do too. i just thought the SC 302 might be easy. but it looks like it must be a lil less reliable than that 351. i know about upgrading the tranny and axles, but i dont have the cash to do motor and tranny/axles right now. and i like the idea of not having to rev the motor so much. i want a fast car without having to beat on it all the time. know what i mean? i dont want to have to dump the clutch and hole shot all the time to run cars down. so the torque from the bigger motor seems like the better option. and as far as the bottom end goes, do u think its a must to have it forged?

and yes creature comforts are a must too. EFI is going to stay and the AC also if i can get the rest of the parts i need to hook it all up

 

[Venom351R]

and as far as the bottom end goes, do u think its a must to have it forged?

All depends on your power level but unless your running crazy HP I wouldnt worry about it to much. Ive seen pleanty of 5.0's w/ boost at 500 RWHP + with stock bottom ends so I wouldnt worry to much about it with a N/A 351

 

[Chads95GT]

yeah im not looking for crazy horsepower now. maybe close to what your putting down Redline. then maybe over the years i could add to the combo and get close to 400hp, but nothing more than that. how much did you guys have wrapped up in all the little extra things that u forgot to account for during ur builds? an extra $1000?

 

[Venom351R]

yeah im not looking for crazy horsepower now. maybe close to what your putting down Redline. then maybe over the years i could add to the combo and get close to 400hp, but nothing more than that. how much did you guys have wrapped up in all the little extra things that u forgot to account for during ur builds? an extra $1000?

Mine came as it sits now. Only thing Ive done is rear end work and exhuast. The car was dynoed by the previous owner but from my track time and trap speed Id say its pretty accurate but Im going to get it done myself this summer as well. In addition to whats on the car now Im planning on putting on a Trick Flow R intake for the 351W and a Custom Grind cam. I want to get as close to 400 HP N/A As possible. Those new Digital Mass Air Meters are looking pretty sweet as well.

 

[Chads95GT]

redline, what kind of gas mileage do you get? and i imagine you have traction problems, but how bad it is? i was thinking about going with 3.55 gears to help with that. are the roush headers a shorty header?

 

[HGFireHazard]

I assume this isn't your sole mode of transportation and is a fun toy to take out when you please?

I can tell you that all new parts and supporting mods just for the vortech (including tune) cost me almost $6,000. The car is pretty reliable and I really love to drive it, but I might have to vote for the larger motor in your case.

I've had my plans laid out for the most part before I started modifying the car. I knew my end power goal and I knew a pretty good road map for how I wanted to get there.

Now, on to what I consider a just as important issue as your choice for platform: if you don't have enough money to beef up the things that will break eventually under that power, are you going to be able to deal with the downtime until you get the money to fix it?

I'm a big advocate for building cars with supporting hardware first. What happens if you blow out your rear end, transmission, or clutch when you're on one of those long trips you spoke of?

It's something to strongly consider. All that power under the hood is awesome to play with and it's something most of us here want, but you can't expect stock components to handle all of that for too long.

In any case, with the wants you listed I feel that the 351 is a better choice for you.

 

[Venom351R]

redline, what kind of gas mileage do you get? and i imagine you have traction problems, but how bad it is? i was thinking about going with 3.55 gears to help with that. are the roush headers a shorty header?

Been so long since I have driven it that its hard to remember. I think Im getting around 200 miles to a tank but dont quote me on that. Im not sure how well the car is tunned at the moment and Im sure its in need of a new fuel filter. The traction is alright w/ the Nitto's on the street, it hooks up hard at the track with the MT ET Streets. My Nitto's are virtually bald right now so Im looking at getting some Good Year Eagle F1 GS-D3's just for reg street use. The Roush headers are shorty headers, I heard they are very hard to come by and sell for about $600 used so I dont think I'll be getting anything different.

 

[Chads95GT]

HG, yes this is just my summer car. the down time will suck, but atleast i have another vehicle to drive. the clutch will get replaced when the motor goes in, but the tranny and rear end will have to be later. i understand what u mean though by getting all the power and then everything else breaking. maybe i will just save some more til i have enough to swap everything over. its just im sorta in the need of an engine now. do you think as long as i drove the car "normally" my T5 would hold up? and what would i need to beef up in the rear end? im giving it a rebuild in the next month or so, but i wasnt going to upgrade to 31 splines or anything.

 

[BlackVert]

i supercharged my 302 with a kenne bell. blew up my motor after about 3 months because there was a vacuum leak i could not find.

n/a is generally agreed to be more reliable than supercharged.

if i were doing it again, i would probably drop in a stock bottom ended 351 with some used decent heads off corral and a reasonable cam. that would yield good power, be very streetable and be easy enough on the tranny that you can avoid having to upgrade the tranny immediately.

to just get the 351 in and get it running is a great start. then after getting the bugs worked out, you can have fun driving it while saving for a stroker rebuild and tranny upgrade.

 

[HGFireHazard]

HG, yes this is just my summer car. the down time will suck, but atleast i have another vehicle to drive. the clutch will get replaced when the motor goes in, but the tranny and rear end will have to be later. i understand what u mean though by getting all the power and then everything else breaking. maybe i will just save some more til i have enough to swap everything over. its just im sorta in the need of an engine now. do you think as long as i drove the car "normally" my T5 would hold up? and what would i need to beef up in the rear end? im giving it a rebuild in the next month or so, but i wasnt going to upgrade to 31 splines or anything.

Your T5 could very well hold up until you are good and ready to replace it with something else, but it could also have a synchro go, or maybe even bend splines on the input shaft, there is just no way to tell.

It's best to look at things for the purpose. You aren't going to put in a more powerful motor to lug the thing around everywhere at 1/4 throttle. You're going to give it hell, aren't you?

I don't want to deter you from your plans (I hope to see you put a 351 in...), but I hope you also realize the potential for problems.

If you were going to rebuild the rear end, it would be a good time to take some of that money and go 31 spline. That's what most of us do when upgrading the rear. You just need a differential, a set of gears, and some axles. I believe you can also purchase fully loaded carriers, but that would be up to you. Someone could give you more accurate pricing than me.

It's amazing how quickly a lot ($6k) of money can go but to me it's all worth it.

 

[Chads95GT]

HG, ok i got on upgrading the rear end, would you use the 31 spline trac loc? or would u an aftermarket diff? and do i need a new carrier or will mine work?

Black Vert, and to all the others what kind of heads would you recommend?

 

[Pokageek]

I would not recommend upgrading the rear axle. You do not need 31 spline unless you are going track. All you need to do for insurance and a low budget is weld the axle tubes and tq boxes and yo uare done.

 

[Chads95GT]

pokageek, see i thought the same thing, im never going to run slicks and try a launch it. i can see is point as to upgrade them for ease of mind and safety. but at this time its not in my budget, i want to get the motor in and running. i've read through some of your PIA swap thread. is it really that frustrating?

 

[HGFireHazard]

pokageek, see i thought the same thing, im never going to run slicks and try a launch it. i can see is point as to upgrade them for ease of mind and safety. but at this time its not in my budget, i want to get the motor in and running. i've read through some of your PIA swap thread. is it really that frustrating?

I re-read your initial post and see you put that it will never see a track. Rebuilding the traction lok and welding the tubes and torque boxes as Pokageek suggested is perfectly acceptable

 

[BlackVert]

Black Vert, and to all the others what kind of heads would you recommend?

oh ... trick flows, edelbrocks, afrs, canfields, ... they are all alot better than stock E7s. even GT40 heads

see what people have up for sale.

i did way too much all at once, and that is one reason why i am still not on the road. that is why i now think breaking it up into smaller pieces is a good approach.