Can You Put Heads on High Mileage car?

[Silver5.0]

Hi I was wondering if I could put heads like GT-40P heads or some other aftermarket heads on my high mileage stang i've got 178,000 miles on it. It runs strong. It's just I don't want to blow up the bottom end up. I have exhaust and rearend gears and things like that but no engine modifications. Thanks for your help.

[Unit 5302]

You COULD, but I wouldn't if I were you. Even if it's running strong, you've got some piston ring and cylinder wall wear going on. GT-40P heads will increase your compression, both in cc size, and in sealing of the valves.

That's a lot of extra pressure to put on an engine. Besides, you can buy a new GT40P longblock for about $1800. I'd save up for that.

[Silver5.0]

Where could I buy that GT-40P longblock at? Thanks

[Coupe5oh]

look in magz, CCH, forgot what company's,

btw, i talked to a guy at the track that said he took a 5.0 with over 180k miles and slapped heads on it, and ran the crabp out of it with slicks, dont know how long it lasted, but he said these 5.0's are indestructible, which i agreed, but still would recomend a prepped shortblock.

[Dark_5.0]

I would run a compression and a bleed down test and if those come out ok I would just slap those heads on there and go have some fun.

It could last for years.

Later,

[Mr 5 0]

Silver5.0:

You can install GP 40 heads and probably the worst that will happen is that you'll end up getting (oil) blow-by - but maybe not for awhile. No guarantees with that much mileage on the block.

For all the work involved in removing and installing new heads (on a high mileage block) I would take Unit 5302's advice. Do it right the first time; go for a new longblock.

[Skyman]

You can get that longblock from Muscle Motors I know In CA.

1-818-888-7778, Ask for Jack

Skyler.

[Silver5.0]

Thank you guys for your advice, I still haven't decided though but thanks again.

[Dark_5.0]

What world do you guys live in. "Its only 1800.00 dollars"

Many people are running heads on high mileage blocks with "No" problems.

If it were me I would run a compression test and if the results were good I would throw those heads and what ever else you want on that block.

If you have the money to blow on a block. Go for it, but I wouldnt do it unless you have to.

Later,

[ballistic_331LX]

IF YOU HAVE GOOD COMPRESSION....ANYTHING ABOVE 110PSI...IT WOULD BE OK TO THROW A SET OF HEADS ON A HIGH MILEAGE CAR......I HAVE DONE IT AND IT HELPED ALOT.....JUST DO NOT THINK TO HARD ABOUT IT AND FRY YOUR BRAIN...RTEMEMEBR TO DO THE UPGRADES AROUND THE HEADS ALSO

[5ohCOUPE]

I have 178K on my car and look at my SIG. I have no problems with my bottom end and its been over a year sence ive put all the mods on it. Ive also have run about 50 bottles through my motor too !!!!!!!!!! But too many T5's broke on the bottle so I took it off. I say what the hell, put the heads on it.

[HORSEMEN RACING]

High mileage 302? Definitely give it a compression test,if it is okay watch the oil comsumption,and have fun,most of the Factory Stock cars in NMRA are running either GT40p heads,or ported E7 heads and they are running low 12's high 11's with 100k mile blocks,so with anything it is 6 in one hand,half a dozen in the other your motor might let go on the first pass it might let go on the 100th pass,Be Afraid,Be Very Afraid LOL

1800 dollars for a long block? What type of pistons does this thing have? If it is the glass-jawed hyper-pathetic pistons I would steer clear of that thing like a minefield in Afghanistan,I just got my 2000 GT back today and that is what was wrong with it a piston took a crap,car only had 20k miles on it lucky for me warranty is good for 75k miles

[Skyman]

Dont listen to this bad information. Hyper pistons are fine, Ive seen cobra motors go 9 seconds on them. And those cars are NOT running on 100k shortblocks.

Skyler

[Unit 5302]

There is NOTHING wrong with a mild N/A setup on hypereutic pistons.

Most 5.0HO's (in my personal experience) begin to drop off at about 120k. While a few stay good to 170k, not burning a lot of oil related to the rings even, there can certainly be other issues. Cam wear, bearing wear, bottom end problems, etc.

A compression test is only accurate about the current combo. If his heads need the valves ground his rings could still be good, but the valves could be leaking. There are just way too many variables for anybody here to come out and say slap heads onto an old 5.0.

Not to mention his intake isn't good enough to support them, anyway.

Let's see, a fully assembled cammed, long block with the heads for $1800. All new components vs an old, worn stock cam, lifters, rockers, timing chain, bearings, pistons, etc. If you're going to build an engine, I say do it the right way so you don't wind up ripping it back down two weeks later. Too much of a gamble for me.

[Stroked408]

Quoting Doug Stanley Ford in south east Dallas,
we have replaced close to 50 modular engines in Mustangs,and T-birds,
now my car is no where near a 9 sec car I admit,but I know a busted piston when I see one,have mod motors been in the 9's definitely,but lot of guys have replaced the pistons,and when the warranty runs out on this thing,I am doing the same,Lidio Icobelli I think that is his name has a supercharger on a stock Cobra engine that runs 9.40's is he playing with a hand grenade I think so,can Lidio replace it at anytime oh hell yes he can LOL,just an opinion on the hyper-pathetic pistons not fact,just opinion

[Unit 5302]

Originally posted by Stroked408
Quoting Doug Stanley Ford in south east Dallas,
we have replaced close to 50 modular engines in Mustangs,and T-birds,
now my car is no where near a 9 sec car I admit,but I know a busted piston when I see one,have mod motors been in the 9's definitely,but lot of guys have replaced the pistons,and when the warranty runs out on this thing,I am doing the same,Lidio Icobelli I think that is his name has a supercharger on a stock Cobra engine that runs 9.40's is he playing with a hand grenade I think so,can Lidio replace it at anytime oh hell yes he can LOL,just an opinion on the hyper-pathetic pistons not fact,just opinion

That's quoting you, and this is quoting me:

A 9 SECOND CAR IS NOT A MILD N/A COMBO!!!!!!!!!! RACE CARS WITH $20,000-$50,000 ENGINE COMBOS NEED THE HIGHEST QUALITY PARTS TO KEEP FROM BLOWING UP. A 320HP 5.0 DOES NOT.

[HORSEMEN RACING]

you know what was I thinking,why did I even take it to the shop,all the Ford tech's are right here in this forum. I am not being a wise guy or smart-alic but when a Ford tech at a Ford dealership tells me a piston (a hyper-pathetic one at that) goes bad I am going to tend to believe him,when a speed shop tells me the pistons are crap I am going to believe them,when a piston in a stock 2000 GT goes bad after 20k miles no one can tell me that piston is not crap,when every Ford publication I read says be careful with the glass-jawed pistons I am going to believe them. Are there cars out there going fast with a stock bottom end......of course there are,are most of those guys running their own speed shops or know someone that is you bet there is,gents you can say what you want,just as I can,I know what I seen at the dealership when they took the motor apart,and showed me what the piece of crap looked like,no one is going to tell me about bad information when I seen it with my own eyes,give that one up and do not go there with this one,I am easy to get along with but do not tell me what I did not see with my own eyes.
Now there are fast guys out there with mod motors like Lidio,Paul Svnicki,Barry Shephard,and John Mihovetz,and JR Granatelli that are running incredible times with the mod motr,I like the mod motor if I did not I would not be paying.........LOL never mind will not reveal that..........but I do not like the pistons bottom line

[Unit 5302]

Originally posted by HORSEMEN RACING
you know what was I thinking,why did I even take it to the shop,all the Ford tech's are right here in this forum. I am not being a wise guy or smart-alic but when a Ford tech at a Ford dealership tells me a piston (a hyper-pathetic one at that) goes bad I am going to tend to believe him,when a speed shop tells me the pistons are crap I am going to believe them,when a piston in a stock 2000 GT goes bad after 20k miles no one can tell me that piston is not crap,when every Ford publication I read says be careful with the glass-jawed pistons I am going to believe them. Are there cars out there going fast with a stock bottom end......of course there are,are most of those guys running their own speed shops or know someone that is you bet there is,gents you can say what you want,just as I can,I know what I seen at the dealership when they took the motor apart,and showed me what the piece of crap looked like,no one is going to tell me about bad information when I seen it with my own eyes,give that one up and do not go there with this one,I am easy to get along with but do not tell me what I did not see with my own eyes.
Now there are fast guys out there with mod motors like Lidio,Paul Svnicki,Barry Shephard,and John Mihovetz,and JR Granatelli that are running incredible times with the mod motr,I like the mod motor if I did not I would not be paying.........LOL never mind will not reveal that..........but I do not like the pistons bottom line

I'll tell you something right now. Don't believe everything some dumbass Ford tech tells you. Also, might want to see a few of the people on this site who've been spraying 125-150 shots on the hyper pistons for the 5.0. Members with blowers, and pretty decent N/A setups too. As far as the mod motors go, you're talking a totally different animal. That's a discussion best carried out in the Modular Madness forum, which is why the forum is on the site.

People who know what the hell they are talking about are here. But hell, I've only spent 3 years and 5000 posts researching and answering questions about the 5.0. What the hell do I and the other guys who've spent years and thousands of posts answering tech questions on this site know? Nobody is forcing you to learn. You can go right back to talking to some moron Ford tech will all the answers who's buddies buddy once heard of a kid that burned a hyper piston just because the piston was cast. Do hyper pistons fail? Yep. Do forged pistons fail? Yep. Are hyper pistons good on mild N/A combos? Yep.

You're the kinda guy who has no clue about what they are talking about, but presume to be an expert because a Ford tech told you so or some magazine article with a washed up old mechanic said so. I got news for you. I was in the same boat a few years ago when I joined this site. If you're not willing to hear the true facts, swallow your pride, and feel like an idiot a few times, leave. Nobody on this site, including myself is going to bend the truth for you to feel better. People are out there counting on us to give them good advice; in some cases advice which could make or break their total budget. It's a responsibility many of the VERY well informed moderators, senior members, and even junior members take seriously. There has been more BS spewed out like it was general knowledge about the Mustang 5.0 than about any other engine in history.

[srv1]

Horsemen. no one says that what you said was "false" in a direct way. and also, anyone can become a Ford Tech. doesnt mean that they know "Fords" the best either. not all speed shops think the same either. not a speedshops are good. hypers are not junk. if you want to run a race motor then yeah put in the forged. i know many people with the hypers in the mods using spray with no problems at all. i guess you just have to know what you are doing.

excellent point Kell.

[Unit 5302]

By the way, there is almost ALWAYS a new know it all joining the boards who really has a lot to learn. If they stick around, they learn a ton, and very fast if they care to. Eventually they figure out a lot of us know what we're talking about.

Lemme throw a few BS 5.0 Tales out your way.

#1 The Fox Body Mustang GT weighs 200lbs more than the similar LX 5.0.

False. The true weight difference is closer to 20lbs.

#2 The 1987-1988 (non CA) Speed density 5.0's cannot except heads, cams or in some cases even intake modifications.

False. With a few minutes of tuning, speed density has proven itself with solid aftermarket heads, mild cams, and aftermarket intakes.

#3 The stock fuel injectors (19lb) must be upgraded when you use a mild to moderate N/A combo, or mild blower.

False. Properly functioning 19lb injectors will support around 350hp on a N/A engine with an adjustable regulator.

#4 The heads are the weakest part of the 5.0 combo.

False. The stock intake flows much worse than the heads at about 135cfm. The heads flow 155cfm.

#5 The HO cam is weak, and for a car to run quick an aftermarket cam must be used.

False. The HO cam has been putting full weight Fox cars into the 12's for a long time. It's the strongest part of the HO intake/cam/head combo.

#6 The 1993 5.0's cast piston's are what caused the lower 205hp rating.

False.

#7 The 1993 5.0's were rated by "average performance" a new Ford rating method which caused the hp rating to drop.

False, technically.

#8 The 1993 5.0's had less power than a 1988 CA to 1992 5.0.

False, technically.

The true answer to those questions is that the 5.0 was never rated from 1988-1992. Ford simply carried over the numbers dispite adding MAF, detuning the computers, making revisions to the air silencer, and the camshaft, along with other minor details. In truth, the 93 5.0's cast pistons would have made MORE power due to their lighter weight. Unfortunately, warranty claims caused Ford to detune the computers and the SN95 cars carried that trend out. In all reality, the 1988CA - 1993 5.0HO MAF engines should make the same power, with the same computer of course, and assuming the engines are built to the same degree of accuracy. There is no 20hp difference between the 93 and 92 cars, and Ford's reasoning is bogus. Dyno tuners know the 93 isn't 20hp weaker than a 92 car, and the dragstrip times prove it. It was all a bunch of BS to justify the lower rating when Ford re-rated the engine.