81' stang w/ 351w questions

[81stang351w]

Hey everybody,
I have a 81' stang with a 351w project I am in the middle of, I am working on getting 400bwhp. I am trying to keep it in a reasonable budget as well. stats: roller 351w carb, gt40 heads, bbk headers, mild cam, c4 tranny w/ 2200 stall stage 2 kit, high rise intake,750 holley double pumper, fresh build on the whole motor. I am also doing all the nuts and bolts stuff myself, it will visit the track occasionally but will be mostly a street stang. I would look at getting a bigger stall, radiator, heads, etc. I also looked into the nitrous option, and have experience with it, but am not sure what the windsor can take. any idea's and suggestions would be much appreciated!! thank you very much. also the rear end is 3.55 gears with posi, (rear out of a thunderbird), 2" lowered, factory suspension, I know i will also need to update the suspension with coilovers any suggestions would be great also!! thanks!!

 

[NIKwoaC]

Definitely going to need better heads than those GT40s to reach your goals. I would be considering a head that flows 300CFM or better by .600" lift, and those 40s aren't even coming anywhere near that.

Get yourself a good cylinder head, then find someone to grind a custom cam for you. Tell them your goals and they will help you get there.

I don't know much about carbs, maybe someone else can chime in there.

If you're planning on spraying it, or going with any means of forced induction, you'll need forged pistons. Stock 351 pistons are cast and they won't hold up to much. That said, the rest of the 351 if pretty tough, and I've seen the blocks handle 700hp and up. After the pistons, the next weak link are the rods, so keep that in mind, too.

 

[81stang351w]

I was checking out the Aluminum ford racing heads or the trick flow twisted wedge, and definately planned on dumping the sufficating gt40s. what kind off pistons would you recommend and anybody know what volume of spray the motor can handle with different pistons and rods? thanks for the replys so far, still looking for any help info, thanks!!

 

[ID89GT]

I would call someone and pretty much tell them what you want and what they recommend to get there. Rick would probably help out a lot

 

[gearheadboy]

Is the motor really in the car yet? I'm curious about a windsor with those heads and swap headers. What are you using if it is in there and if it isn't, have you thought about that?

 

[86bluecobra]

Personally I would be looking for a used set of Vic jr heads for a project like that. had a set of holley heads on my 351w with a dual plane intake when I went to Vic jr top end I picked up 6 mph. I am using the same cam. Don't skimp on heads they are wants going to help you make the most power out of the engine.

 

[Rick 91GT]

I personally would look into a 200cc+ which will work fine now and in the future. The 750 is a little large right now...

 

[Rick 91GT]

If you need help with parts or some recomendations let me know if I can help.

Rick
Owner/ Operator RNH Performance
[email protected]

 

[86bluecobra]

I personally would look into a 200cc+ which will work fine now and in the future. The 750 is a little large right now...

what really is the downside of over carb'ing? Is it just idle issues? I have seen dyno runs where numerous carbs were tried up to 1050's and once the motor made peak power the bigger carb's just made the same power as the smaller carbs. Just curious.

 

[Rick 91GT]

If a carb is to large you end up putting large jets in to pull on the carb hard enough.

Fwiw- I had a 408 on the engine dyno with a 750 holley and pulled 4 jet sizes down...very efficent motor made 539/589.

 

[86bluecobra]

OK sorry for my ignorance but I'm curious what you mean by pulling on the carb hard enough.

 

[Rick 91GT]

To get the proper signal for the fuel circuits.