Afr Heads Help

[Undr-psi]

I know this subject has been beat to death but I'll ask it anyways. I have a 91 coupe with stock bottom end 302,e303 cam,v3-s-trim blower making a little over 500 wheel. I've got a set of afr renegade 185cc heads im about to get on a trade and was wanting some advice on if I'll have to notch my flat tops in order to run these heads or is it possible to run them without notching or a piston swap which I'd much rather not do. Any solid advice would be much appreciated thank you!

 

[Undr-psi]

 

[FastDriver]

That's a nice engine bay, buddy. Welcome to the site. You'll need to notch those pistons with the AFR185 heads and an e303 cam. Sorry for the bad news. You say you have flat tops, but even the valve reliefs on stock 87-93 short blocks need to be notched a little more to work with that combo of heads/cam. AFR 165s would not require any notching. TFS twisted wedges also would not require any notching. 500rwhp stock block limit can be reached with either head on reasonable boost. Consider trading down or buying one of those tools that lets you notch pistons while still in the short block. Hope to see more of that build.

 

[Undr-psi]

That's a nice engine bay, buddy. Welcome to the site. You'll need to notch those pistons with the AFR185 heads and an e303 cam. Sorry for the bad news. You say you have flat tops, but even the valve reliefs on stock 87-93 short blocks need to be notched a little more to work with that combo of heads/cam. AFR 165s would not require any notching. TFS twisted wedges also would not require any notching. 500rwhp stock block limit can be reached with either head on reasonable boost. Consider trading down or buying one of those tools that lets you notch pistons while still in the short block. Hope to see more of that build.

Thank you sir,I think it' rather fancy myself. Bought the car (one owner)stock 8 months ago and she's coming right along. I'll probably will go with with the 185 because eventually I'll change the block up to handle a little more boost. I figured I'll be pushing close to 650-675 at the crank once I get those heads on there and I'll have Chris Tuten put a tune on it that'll hopefully keep it alive as long as I can keep my foot out of it, which I'm not doing a very good job of at the moment.

 

[mikestang63]

welcome to the site. Very nice stang. At 500 rwhp on a stock block I hope you have that Dart block handy

 

[Undr-psi]

welcome to the site. Very nice stang. At 500 rwhp on a stock block I hope you have that Dart block handy

Thanks man.It's been an absolute champ,rev limiter set at 6 grand and it stays on it,lol. We'll see how it handles 575 wheel,or at least thats what I'm thinking I can squeeze! I've got a buddy of mine with a 150 shot on his stock block putting 615 to the wheels,those old 302's are tougher than most think.

 

[Undr-psi]

 

[Undr-psi]

 

[2000xp8]

Honestly, it's a bad plan, period.

The damage a split block does isn't restricted to the block and rotating assembly. You will lose the oil pan (if it's a good one), damage the heads and break the lower intake.
Even worse, one of the buddy's cars had the front end of the crank come off with the pulley and hit it with the rear wheel.

Just build a completely new engine on the side if you really need more than 500rwhp.

You have a nice car, now picture it on jackstands for the next year because you made changes that weren't really necessary or advisable.

 

[Undr-psi]

Honestly, it's a bad plan, period.

The damage a split block does isn't restricted to the block and rotating assembly. You will lose the oil pan (if it's a good one), damage the heads and break the lower intake.
Even worse, one of the buddy's cars had the front end of the crank come off with the pulley and hit it with the rear wheel.

Just build a completely new engine on the side if you really need more than 500rwhp.

You have a nice car, now picture it on jackstands for the next year because you made changes that weren't really necessary or advisable.

You know I think that may be my best bet,

Honestly, it's a bad plan, period.

The damage a split block does isn't restricted to the block and rotating assembly. You will lose the oil pan (if it's a good one), damage the heads and break the lower intake.
Even worse, one of the buddy's cars had the front end of the crank come off with the pulley and hit it with the rear wheel.

Just build a completely new engine on the side if you really need more than 500rwhp.

You have a nice car, now picture it on jackstands for the next year because you made changes that weren't really necessary or advisable.

Im starting to think thats maybe the way i should go. I just got the heads,so maybe now I should start looking for a block and some internals. I can't help myself,I just keep wanting more and more powa out this car but at the same time I don't want to cause more damage than good. Thanks for input

 

[Steel1]

Get a 351 block and build it with compression for boost, those blocks are affordable and
will handle the power levels you'll be putting out.
I built a 351 (1969 block) based n/a stroker with 10:5:1 and have been very happy with it!

 

[Undr-psi]

Get a 351 block and build it with compression for boost, those blocks are affordable and
will handle the power levels you'll be putting out.
I built a 351 (1969 block) based n/a stroker with 10:5:1 and have been very happy with it!

You know I just so happen to have a buddy of mine with a 351 that's already built that he decided not to use and he's been trying to get me to buy it from him. I might just go that route. I was just kind of partial as to keeping a 302 in the car

 

[2000xp8]

What exactly is it that you are searching for?
Sounds like you have a car that is powerful and runs well.
If you think another 50 to 75 rwhp is going to somehow satisfy your needs, it's not happening.
500 and 550rwhp is pretty much the same on the street.

I can't see a real world use for an aspirated 351 either, when you could just simply build a dart 363, swap your current parts and be done.

My advice, leave it be or you will spend another 10 grand and land up with a car that feels the same or worse as what you have now. It's just too much money and trouble for too little gain.

I really do understand the desire to change/modify things, what do you have for brakes? Suspension? Chassis?

Chasing big numbers has ruined countless numbers of fox mustangs over the years.
It's taken some of us older guys around here years to realize that there is more to a car than just some insane number printed on a dyno sheet.

 

[Undr-psi]

What exactly is it that you are searching for?
Sounds like you have a car that is powerful and runs well.
If you think another 50 to 75 rwhp is going to somehow satisfy your needs, it's not happening.
500 and 550rwhp is pretty much the same on the street.

I can't see a real world use for an aspirated 351 either, when you could just simply build a dart 363, swap your current parts and be done.

My advice, leave it be or you will spend another 10 grand and land up with a car that feels the same or worse as what you have now. It's just too much money and trouble for too little gain.

I really do understand the desire to change/modify things, what do you have for brakes? Suspension? Chassis?

Chasing big numbers has ruined countless numbers of fox mustangs over the years.
It's taken some of us older guys around here years to realize that there is more to a car than just some insane number printed on a dyno sheet.

Well said. I've definitey got other areas that could use some improving on. It' just been fairly easy to get the power out of it that I have now so I guess I was just searching for what else I could get out of it but it's looking like I've maxed out the current setup(safely anyways) that I have. Im sure ill be starting with a block and peice together slowly something that will handle wgat im searching for. Not a thing wrong with wanting a 700+ rwhp fox

 

[mikestang63]

Agreed- your car makes more than enough power to overwhelm the car as it is. Enjoy it. I actually dialed my car down from 480 to around 450rwhp as it really doesnt make much of a difference at this level and I'd like to try and save the stock block as long as possible.I keep it under 6k and my days of street racing are long behind me.

 

[Steel1]

I'm also at the point where I am happy with 425-450hp and my 393w gets me there without worrying about the block giving up.

My original 70k 302 short block sits safely wrapped up on the stand ready for whatever.
Funny, when I first got the car it was basically bone stock then after many HCI changes, 3 different superchargers and all the other mods to go with it, I think I'm finally satisfied with the power I'm at...just having fun with an n/a weekend cruiser.
Good luck to the o.p. on your decision, sure is fun making power!

 

[Noobz347]

I had all of these quotes picked out as I read then saw that most of what I was going to say has been said.

While you're building that new DART block ( I prefer the low deck-height builds but that's just me ) I would just add:


suspension Suspension SUSPENSION and street cage

 

[Undr-psi]

Agreed- your car makes more than enough power to overwhelm the car as it is. Enjoy it. I actually dialed my car down from 480 to around 450rwhp as it really doesnt make much of a difference at this level and I'd like to try and save the stock block as long as possible.I keep it under 6k and my days of street racing are long behind me.

Well I'm young,dumb,and full of...well you know. So ima leave it be on my current set up and go ahead and start my new build.

 

[Undr-psi]

I came to the site looking for advice with heads next thing I know I'm putting together a short block that can handle whatever I throw at it. This car is worse than a child. It's definitey been a pleasure getting all this good advice and I thank yall. I'll post updates on my progress or any more advice I need

 

[mikestang63]

Well I'm young,dumb,and full of...well you know. So ima leave it be on my current set up and go ahead and start my new build.

Woody is one of the best engine builders around but expect it to take a few months to build. He will build you a fantastic engine but again, he uses only quality parts. That is the problem with these cars, they are black holes that you can easily throw $20000 at