[Mustang 69 Chile]

I have a basically stock 1969, Ford Mustang 302 cid. It has it's orginal motor. I have changed it's rings recently leaving it with a .030" oversize. I used the original pistons and rods. After a visual inspection the components seem to be rather sound. I have been in possesion of the car for almost a year, and have no idea how they treated it before me, but apparently it was not too punished. My plan however is to change some components to have a more high performance orientated setup.

I eventually plan to use nitrous. They have recommended me to change my pistons to forged ones, which is obvious, and also the connecting rods however I am not too certain of this last recomendation, what do you reccomend I do. I do not have an endless budget, although I know that you can't have any thing good cheap, I want best value for money, and not to over spend on an aplication that I will not be using to it's full extent. The use would be mainly high performance street and some drag racing. There is a larger availability and selection of pistons than of rods so from what I can gather

As far as I have learned it is necessary, if not essential, to change my pistons to be able to withstand the increased loads, however I have not been able to gather much information as to what I should do concerning the connecting rods.

Concerning the pistons, I understand the my car came with a stock compression ratio o 9.5:1. To increase performance I undestrand that it is good to increase this compression ratio, however, if I use nitrous this may not be recomenadable, what is your opinion?

I have headers installed and plan to change: air manifold, 700 cfm 4 barrel carb, camshaft, heads... I do not want to stroke the engine. I reckon I should end up with a little over 350 hp without nitrous.

In conclusion how advisable is it to change the connecting rods, is it really worth the effort and what pistons are recomendable for my application.

For more details concerning my car please visit my site: <a href="http://www.kovacic.tie.cl/mustang69/" target="_blank">http://www.kovacic.tie.cl/mustang69/</A> the links on top frame or bar "Model of my car" has my VIN plate information and "Modifications" has what I have done so far and what I plan to do.

I'd be really grateful for any advice on this.

[pontiac man]

If you plan on using the nitrous at all it would be advisable to go ahead and replace the stock connecting rods with a set of H-Beam rods, or something similar. The stock rods may not be able to handle the extra cylinder pressure of a nitrous system. Its far better to spend a little more money now on a set of good rods,rather than the first time you open the nitrous bottle blow a connecting rod through your oil pan. Which will be more expensive to fix than buying a set of rods now. Make sure you get the same length rods you have in your engine now.

[Mustang 69 Chile]

Thanks Pontiac Man!
Between H-Beam and I-Beams, I understand H-beams are stronger, but rather more expensive. Is there any particular rod you might recommend to me. Would an I-beam be sufficient, value for money what do you reckon is best?

[4 Jaw Chuck]

How big a nitrous shot are you considering?

[Mustang 69 Chile]

I plan on using a NOS Super Powershot with 100 Hp, at most 150 Hp. I was thinking of keeping my rods a pistons untill I install the nitrous, I think it should manage, even if I do install a Perfomer RPM Manifold and 4 bbl carb, what do you reckon?

[mustang66maniac]

Stock pistons and rods will handle 350hp as long as you dont rev past 6000. If you put ARP rod bolts in the rods and shot peen them, stock rods and pistons will handle 6200rpm. With rods its not really how much power you are running, but rather, how high you are revving. Running with nitrous is another story. I would think that aftermarket "I" beam rods would be sufficient enough for only a 100hp shot. Just put some good rod bolts in it. As of right now i have a 302 with aftermarket heads, intake, cam, headers and carb running probably about 365hp and i have stock rods and pistons. Its all stayin together, probably because I've only revved to 6000 once only to see if it still made power.
If you are going to add aftermarket iron heads, i wouldn't exceed 9.5:1 if you have aluminum ones you could go to 10.5:1. There is a pretty good selection of pistons out there, to find out your CR you will have to know the CCs of your heads. I think stock 69 302 heads have 60cc chambers and with flat top pistons will create 9.5:1 compression ratio. Watch out for valve clearance if you get into domed pistons.
HAve fun with your project, nitrous is cool!

[Mustang 69 Chile]

Thanks Mustang66maniac! That's round about what I was thinking of doing. Your advice has been invaluable. It's a bit difficult to get good advice here locally in Chile.