Starfury

I agree. That said, I think you need to try to up your budget enough to include some decent heads. Your 289 heads are going to be your bottleneck, even if you open up the exhaust ports yourself. Some GT40 (not GT40P) heads in good shape would be the least I'd recommend, but some good aftermarket heads (Edelbrock, Trick Flow, etc) would be much better. If you look around for a deal, you can pick some up for $1k-1200.

JChase

Would porting a set of GT40's yield good flow? My buddy has a set he'd be willing to give me for some graphic design work. I read the thread on porting and that looks easy enough and I have heads around here i can practice on. Would I have to change the valve springs on the GT40 heads for a E303 cam?

JChase

So i just bought a set of Twisted Wedge Aluminum heads and Stage 1 cam. My question now. Since the heads have angled valves to clear the pistons, should i get flat top pistons to bump compression or stick with the stock pistons? And can I use the stock lifters and the 98 Explorer timing gear and chain? I also swapped to AOD for a WC T5..LOL

OCHOHILL

Trick flow makes several different twisted wedge heads for the SBF. Which ones do you have? Were these bought new or used?

I thought you were using the stock pistons. You can reuse the stock lifters. I would replace the timing gear with one that allows you to adjust the cam timing. I suggest you do some research on

setting cam timing
measuring the combustion chamber and figuring your static comression ratio
measure the spring pressure to confirm it works with your camshaft
measuring for the correct length pushrod
checking piston to valve clearance

I would have kept the T5, but to each his own. There is a cable that must be set on an AOD in order to keep if from burning itelf up. Set incorrectly, the transmission can self destruct in as little as 2 miles. You may need to take it to a shop for that. Later AOD's need a computer to operate them. Do you have one of these AOD's?

The TW heads angle the valves to improve airflow, not clear the pistons.

JChase

A friend of mine took them off of his roller 302 in his fox body, he just got some AFR heads and a custom cam. They are the 58cc heads with 170 intake and 1.60 exhaust runners. They have dual valve springs on them with 7/16 studs and TFS 1.6 roller rockers and the TFS stage 1 cam.

I just put new rings on the stock pistons. So the bottom end has new crank and rod bearings and now new rings with the stock pistons.

I meant I swapped the AOD for a T5. So now I have a 5 speed to bolt up to the 302.

OCHOHILL, Ill start researching so I can get some sort of idea what Im doing. Thanks for the help

Starfury

Technically true, but piston clearance is a side effect. Due to the 'twisted' valve geometry, you get more piston/valve clearance throughout the engine's rotation cycle than you do with inline valves. This allows you to run these heads on pistons without valve reliefs with up to .540" lift, depending on the specific cam grind. However, when you do start to run into clearance issues, TW heads require different flycuts than standard inline valve heads would.

Stock pistons will likely result in a lower-than-ideal compression ratio. Personally, I'd start with a set of good hypereutectic pistons (economical, but stronger than standard cast) so you can bump the CR up closer to the 9.5:1 range. You do need to figure out which TW heads you have, however, because there are multiple combustion chamber volume options.