what kind of #'s expected with a 351 swap

1993c0bra

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Mar 30, 2005
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Im looking into swapping a 351 into my next stang, and im going to start buying parts now. Im going to have all the necessary parts for it to run strong such as:
Aluminum heads, Injectors,TB Intake manifold, roller rockers, LT Headers, TB, MAF, Cam. Which would be the best parts to get.
Then eventually supercharge it
Damn i really dont want to put a cowl hood on there is their any way around this besides using the solid motor mounts.
What kind of #'s would i lay down also, I want at least 350hp/350tq
 
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With aluminum heads, intake, headers and a good cam you can make 1 rwhp per cube. If you are going to put a blower on you need to buy the large chamber/ low compression heads which will hurt a little. You need a lot of different stuff for the swap, balancer and flywheel are balanced different, headers and intake are different. It's much cheaper to put a stroker kit in your 5.0

Dan
 
1993c0bra said:
Im looking into swapping a 351 into my next stang, and im going to start buying parts now. Im going to have all the necessary parts for it to run strong such as:
Aluminum heads, Injectors,TB Intake manifold, roller rockers, LT Headers, TB, MAF, Cam. Which would be the best parts to get.
Then eventually supercharge it
Damn i really dont want to put a cowl hood on there is their any way around this besides using the solid motor mounts.
What kind of #'s would i lay down also, I want at least 350hp/350tq

I am in the process of putting a 408ci stroker in my 90GT and I am tring to get away with out buying a new hood what I am trying to do is space the back of the hood and take the liner and cut the brace out of the hood. I also have a 393ci short block for sale. I have the details in the NW classified or if you would like the details PM me. the combo that I have put together I am hoping to make 500hp at the motor vic jr heads trickflow intake etc...
 
IMHO 1 hp per cube sounds about right for a good driver, you could get more but at a cost... thats na by the way. With 6-8 lbs of boost you could figure another 80-120 hp on top of that.

I do however disagree with Dan, as long as you are running a reasonable amount of boost (to me thats less than 12lbs) you should be able to run a good set of heads.
Just do your homework: polish the valve reliefs, deburr the edge of the chambers, remove the extra threads from around the plugs, polish the chambers, etc... (personally I would run an intercooler on ANYTHING that was boosted, but thats just me)

If you really want to be anal you can have the tops of the pistons, the bottom of the valves, and the inside of the chambers coated, but thats waaaaaay overkill for a street motor.

You shouldn't have any problems meeting your goal, but you might want to inform youre engine builder, that you are aiming for 400-450 at the wheels, so that way the bottom end is able to handle the blower.

My .02
Dave-
:nice: :flag:

Oh.... PS, if that 351 becomes a 393 or a 408 along the way, then better call the builder and mention the magic 500 number.
 
1993c0bra said:
what does deburring the edges of the chambers do for ya.

Any sharp edge, wheather its on the head, the piston, the valve, whatever... will be a perfect spot waiting to glow red hot. Great source for ignition to occur OTHER than the sparkplug.
Ya dont have to grind on it, just lightly radius (that was LIGHTLY) the edge with a sanding roll.

DD
:flag:
 
My 351 combo has about that rwhp, now. It is what has been described above with the possible exception of small heads (Edel RPM's) and a very old intake (there are much better ones available now). With a carb, my car would probably go .3 quicker (maybe more).
 
Dave, how can you go with 12 pounds of boost with the high compression heads? I have been talking to all the blower manufacturers telling them my setup and they universally agree that with the high compression heads the most boost I can use is 6-7 psi or 8 with an intercooler.

Dan
 
84Gt350 said:
Dave, how can you go with 12 pounds of boost with the high compression heads? I have been talking to all the blower manufacturers telling them my setup and they universally agree that with the high compression heads the most boost I can use is 6-7 psi or 8 with an intercooler.

Dan

what do you consider high compresion I was running 16 lbs boost with 9.5:1 compresion and the thing ran hard in fact the motor I just put together has -12cc dish with 60cc chamber comes out to 10.7 when I put my 70cc chamber heads on that will drop compresion to 9.6:1 or there about and I plan on putting a T88 turbo on. it is not the compresion that kills you it is making sure you have a fuel system to handle the power out put and watching the tune. lower compresion gives you a little more of a cushion. if anything going a little more compresion will make the motor more responsive on the bottom and more HP on the top there is my 2 cents :D