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