Notch pistons for AFR 185's?

[68EFIvert]

I have stock pistons in my 1990 5.0 block and am thinking of changing my heads from Y303's to AFR 185'5 or 165's. Do you have to notch stock pistons to use the 185's? Which head would be best for my combo? I am open to other head suggestions. Would I experience much HP gain with this swap over my existing heads? Here is what my combo currently is.

E303 cam, Professional products intake, 75mm throttle body, 76 mm MAF with inlet tube, 1.7 rr, 24 lb injectors, the internals have been balanced, underdrive pulleys. It is in a 68 mustang convertible that is mostly weekend use. Nothing to extreme. I think I will add a Zex wet system in the future. I wuold like to stick with pedestal rockers since I have new 1.7's and don't want to invest in a stud setup. Thanks for the help.

 

[samickguy15]

I think your pistons will be fine as long as you stay with your cam. You may want to call AFR before you buy the heads and ask them. They will know better than anybody.

 

[5spd GT]

As you know, measuring is the only true way to know if it will safely clear.

The AFR 185's have the 2.020" intake valve, which causes the radial of the valve to go beyond the factory valve refiefs (unless you have aftermarket pistons).

I think AFR 165's would be nice (clearance wise), but you may only see a 20-25hp difference Is that worth spending $1,400?

The emissions legal AFR 165's and 185's have pedestal mount provisions, with a 60cc head. Now, the non-emissions heads do not have pedestal mount provisions. I like the emissions legal heads anyways with the smog holes. They seem to carry a bit more resale value...

Maybe if you have that much money to burn, put your money towards a small supercharger:

Vortech S/C Trim or Vortech S Trim...

 

[68EFIvert]

5 spd gt, You are probably right about the supercharger. I probably would get more HP per $ spent with that. I wonder if a small supercharger would be ok with 24 lb injectors or if I would need to go to 30's? Do kits come with new injectors?

 

[5spd GT]

5 spd gt, You are probably right about the supercharger. I probably would get more HP per $ spent with that. I wonder if a small supercharger would be ok with 24 lb injectors or if I would need to go to 30's? Do kits come with new injectors?

I believe some kits do, like Kenne Bell, or just a call to the distributors and they may be able to hook you up with a deal on the injectors.

You need to be looking at atleast 30lb injectors for a supercharged combination.

If it is an option for you, go with 42 lb injectors and get a tune. They will have all kinds of room for you to get tuned with. You will need a bigger fuel pump, more than likely - 255lph.

Your right, your hp/per $ spent will be much greater, maybe 4-5x that of just the AFR heads.

 

[68EFIvert]

So if I go supercharger I think i would likely have to upgrade the pump as you said. I am currently running this MSD pump http://store.summitracing.com/partd...rt=MSD-2225&N=700+4294836965+115&autoview=sku

Summit says that is is good for 500 hp. More than I will ever make with my combo but I don't know if I need more fule flow with a blower. It looks like it may be time to step up to an Aeromotive 700 hp pump. I can't run and in tank pump since the car is a 68. What do you think?

http://store.summitracing.com/partdetail.asp?autofilter=1&part=AEI-11106&N=700+115&autoview=sku

 

[5spd GT]

That is about a 162 lph fuel pump. I think you need to go bigger for an external eccentric pump...

Maybe someone can help you with a supercharged mustang in the Classic Forum can help you out, if they have a similar combo.

I'm not adverse enough to tell you fuel requirements and needs, where I feel safe doing it, because it is your money and your car. I would hate to blow up both