Easy button 300HP+?

joemomma · Mar 24, 2021

So, I've been watching the Youtube lately and have caught the Richard Holdener channel. He does quite a bit of testing on SBF stuff, including on the 302. Many of his videos mention the Exploder (GT40) intake/heads combo. Basically, the Exploder engine plus a decent cam with new springs in the heads and you're well over 300 - seems like some of them were pushing 350ish. I know that's on an engine dyno with minimal accessories, but you get my point. For less than the cost of a new intake manifold, you're in the game with considerably more power.
Why doesn't everyone (on a budget like me) do this? What am I missing? I get the risks with buying a used engine, but assuming you find a decent lower mileage one what's not to like here? Just a quick search on car-part and I found several for around $500 within an easy drive, with half my current (155k) mileage.
I'm thinking this would be what's needed:
Exploder engine from salvage (includes the complete block, intake, heads, etc)
Decent cam
Springs for the heads
Tune
What am I missing? Possibly new injectors, FP, MAF?

ttocs · Mar 24, 2021

its one of the oldest upgrades for the 302 and done every bit as often as the PI upgrade for the 4.6

PinkieT · Mar 24, 2021

Add too much nitrous and you WILL have an "Exploder"!

joemomma · Mar 24, 2021

LOL.

So, with the heads requiring new springs, is there any benefit to going ahead and doing new rockers while you're in there? I'm thinking it would be prudent to do what you can while you're in there already? Springs, rockers, what else?

tvsn95 · Mar 25, 2021

Look for Cobra rockers, do the T Moss port work, pick a cam thats a bit more than what you think you need, and with more exhaust than intake timing, get springs to match, and diff spring retainers, . HP is in rpm's don't get too scared. you will need to retune. SOOO use 42lb Bosch style inj.
JMHO

Wmac · Mar 26, 2021

Just my opinion, but I think that it really takes some bucks to make the GT40 style heads flow enough to support a "cheap" 300+ hp build. Milling the heads, comp valve job, springs and hardware plus at a minimum a diy port job.
There are some decent "cheap" aluminum heads available these days. Plus you knock about 50 pounds off the nose.
But if $ are an issue, strip the GT40's, lap the valves and seats, check for warpage, buy a spring kit from "Alex", check PTV, find a used cam, home port the heads and the xpoler lower, look for some used 1.7 cobra rockers, used 65mm t/b, clean and use the xplorer injectors and let if fly.
Be aware that GT40p heads will likely cause problems with burnt plug wires/boots.

joemomma · Mar 29, 2021

Found a truck 351 with 180k on the clock for $300. Guy thought it was a 93 or 94 model - apparently there's a big difference between the two as 94 is when hydraulic roller cams began use. I'd need to verify the VIN on the truck, it hasn't been pulled yet. And, it seems that the 351 route is still expensive, as you have to do everything to it that a 302 requires, otherwise, you're just driving a truck motor around.

So, back to the Explorer motor. I'm thinking less than $500 for the junkyard motor, then what - another $500 for head parts and such?

ttocs · Mar 29, 2021

I don't think the 351 option was ever really listed as a cheaper option than a 302, it just gives you more power to start and more room to build up to bigger power in the end.

tvsn95 · Mar 29, 2021

I have done the 351 swap, the 302 front acc mounts CAN be made to work so that you dont go broke trying to find the parts and all will fit like stock. you will need a new dist, unless the truck has one. you verify the Roller motors best with the intake off. the 351 is 28oz balanced so the harmonic and flywheels are diff. not a problem if you have a complete motor. the engine is about 1" bigger everywhere. some cars are tight on one side,,,funny they seem to be tight in diff places , car to car. I guess Ford jigs vary some.
I agree the stock heads are a choke point, and the after market stuff is cheaper in the long run and better/lighter. the intake is a choke point also,,,Read T Moss about intakes

joemomma · Mar 29, 2021

ttocs said:
I don't think the 351 option was ever really listed as a cheaper option than a 302, it just gives you more power to start and more room to build up to bigger power in the end.

Yeah, it seems the block is stronger and there is more potential for big power down the road. The swap sounds expensive from what little reading I've done, honestly.

tvsn95 said:
I have done the 351 swap, the 302 front acc mounts CAN be made to work so that you dont go broke trying to find the parts and all will fit like stock. you will need a new dist, unless the truck has one. you verify the Roller motors best with the intake off. the 351 is 28oz balanced so the harmonic and flywheels are diff. not a problem if you have a complete motor. the engine is about 1" bigger everywhere. some cars are tight on one side,,,funny they seem to be tight in diff places , car to car. I guess Ford jigs vary some.
I agree the stock heads are a choke point, and the after market stuff is cheaper in the long run and better/lighter. the intake is a choke point also,,,Read T Moss about intakes

You have any more details on your swap?