any ford guys out there i need some help.

[Dangerous95lt1]

I recently picked up a 89 fox with a "built" motor. It runs great but kinda backfires around 5500 rpm out of the carb. Its not a severe backfire u can just see pressure out of the carb and it wont rev any higher im thinking valve float but i wanted to see if anyone else has any idea i dont know much about the motor it has a decent cam but dont know specs has roller rockers and arp head bolts.
Any input is appreciated not lookin to dump a bunch of money n this motor because i was do a sbc swap n the future

[2014SS6.2]

If the heads are stock and your cam is over 480 lift, you are floating valves. If it has double springs or manley singles in it, they can usually handle 550 lift or higher with stock valves and guides. If your looking to rev it to 6k your gonna need heads to make any more power. The patriot SBF heads are under $900 and are fully assembled with good stuff. Do you know what push rods or lifters are in it? Ex stock length? Mark.

[popo8]

Ahhh... thats my mustang buddy^^^

[Dangerous95lt1]

I have no idea im gonna pull the valve covers tonight i just thought it should rev past 5500 not that it needs to b turned that high just a thought lol

[2014SS6.2]

Well are the heads iron or aluminum? Maybe GT40p heads? Check em out, tell me what you got and ill tell you what they'll do or what needs to be done to achieve what you want. I dont see anyone building the block and not swapping the heads. The heads on the 302ho engines are the "cock blockers" so to speak lol.

[popo8]

.... The heads on the 302ho engines are the "cock blockers" so to speak lol.

He has always been so eloquent with his wording.... hahahahah

[Madman337]

GT40 heads are marked with a "ZZ" on them, I had a set on my 90 that were extrude honed and running an old school B303 cam and a few other things and my car was still sideways in 3rd gear back in the day.

[2014SS6.2]

Yea def, the P heads are at least 50% better than stock. Def the cheapest way to make power on a budget.

[Dangerous95lt1]

Heads r cast iron ill check em out when i get home

[2014SS6.2]

Ok. Let us know. What size and brand carb is on it? And whats the displacement of the engine?

[Dangerous95lt1]

Looks like stock heads. Springs look very close to coil bind tho. Supposed to b a 347 storker. Im thinking a 302 with a cam lol and edelbrock carb not sure what size

[2014SS6.2]

Well a 347 with stock heads should be close to 350rwhp. With the car being so light, it should be desyroying street tires through 3rd gear. With aluminum heads and a good carb, tuned well it should make over 400rwhp. Is it fast?

[popo8]

Well a 347 with stock heads should be close to 350rwhp. With the car being so light, it should be desyroying street tires through 3rd gear. With aluminum heads and a good carb, tuned well it should make over 400rwhp. Is it fast?

Watch out... POPO30 has a habit of buying mustangs he comes across... lol

[Dangerous95lt1]

It runs ok. Beat my buddys lt1 trans am last night lol!. But its still not faster then my firebird from what i can tell

[popo8]

It runs ok. Beat my buddys lt1 trans am last night lol!. But its still not faster then my firebird from what i can tell

Noooo Nooo Noooo... dont tell him its faster than any LTX.....

lol

[Madman337]

I never raced an LTX powered car with my coupe but did smoke several LS powered cars with mine, the only guy who ever beat me was in a Grand National with an aftermarket turbo and he had me by a car and a half. My car was very light and so it moved out without having to make a ton of power.

[firebird_1995]

Had a collapsed lifter on the exhaust side of a 302 that backfired through the intake but it was very constant.

[Dangerous95lt1]

Mines only at 5500 and my fox is very light too so it don't take much to move it