I have to put a new 390 in my truck. My current engine is about shot (3 cracks on the block, cracked head, warped intake manifold, yeah- the works)

I have a 390 I got from Craigslist last week that I'm gonna put in my truck.

It came with a set of exhaust manifolds (already off!). I also have a set of headers I got for free from a friend. Any benefit with putting the headers in over the manifolds? Would this be ok to do a stock engine? It doesn't have any mods whatsoever.

Just don't wanna mess anything up with putting the headers on.....so do you think it'd be ok to put the headers on?

It's be easy to get the headers on since the engine is already out and all.

 

putting the headers on won't hurt anything,you probably won't gain alot by using them.but if you are planning on doing any other upgrades later,you'll already have the headers on.usually they go good with a cam and intake/carb.really help to wake up improvments like that.but if you have them,and the manifolds are already of the new engine,you might as well put them on while your doing the change over.save you from doing it another time.

 

My truck doesn't have dual exhaust- think that'll hurt anything?

 

Now is also the time to change over to true dual exhaust, turn them out in front of the rear tires to save some money. IMO

Also read up on a cross over pipe, some say it helps?

 

you will definatly have to run duel exhaust once you put the headers on,like F250 said turn them out in front of the rear tires,shouldn't cost much,with a couple of cheap mufflers.I would go to your local auto parts store and buy your pipe too,its usually around $18 here for one ten foot stick of 2.5 inch,and the muffler shop will charge you at least double that.I would say to build it yourself,but if I'm not mistaken its a royal pain in the a$$ to get around the transfer case,and without a bender you'd be into some serious grief.

 

Yeah it's worth it, cause you get to drink beer. (see "need some quick advise bout header install!" thread)

 

Definitely swap to headers, they do wonders over those horrible 'spatula' stock manifolds the FEs were equipped with. Are they longtube of shorties? Since they're going into a 2wd, the only things dual exhaust would have to work around is the trans crossmember and saddle tank if you've got one.

 

ahh for some reason I was thinking it was a 4x4,I put long tubes on my f100 and the collectors were about 3 inches away from my tranny so I nothced my crossmember and rewelded the pieces back in upside down.so I could run my pipes straight through.

 

Here is my modified crossmember.





Wally Womack

 

Wish I would've thought to have done that! The shop just ran my pipes under the crossmember so now my exhaust hangs way too low.
Next set of headers will be fender exit for me...

 

Whichever route you go, take the time to chase the exhaust manifold threads in the heads and make sure you get new grade 8 bolts and anti-seize.
Pro's and Con's:
-The stock manifolds will be easier to fit and you can bolt up your current exhaust
-Headers sometimes create heat problems with the starter
-Headers in place make it harder to get starter in and out
-Headers often have clearance issues with clutch linkages, crossmembers ect.
-Header gaskets have a reputation for leaking, be prepared to revisit you gaskets from time to time.
-Headers look cool when they aren't rusty. Coating them is advisable and an additional expense.
-You may enjoy both an increase in HP and Gas mileage with the headers
-With headers you will need to have a dual exhaust fabricated, a good idea with either stock manifolds or Headers.

I nearly put in headers into my 2wd 390 but stopped short. I did remove a set in a junkyard truck (probably Hedman brand). I needed to use a scissor jack between the frame and the engine block (motor mount to perch un-bolted) to tilt the block up and over a bit to get header in between block and steering gear. About ten years ago on this forum, Jowilker, had two sixties era 352 FE trucks. One had a 4V and Hooker headers, and another was a stock setup. He was reporting at the time that the header route wasn't worth the trouble. I still see him posting on the FE forum.

 

Whichever route you go, take the time to chase the exhaust manifold threads in the heads and make sure you get new grade 8 bolts and anti-seize.
Pro's and Con's:
-The stock manifolds will be easier to fit and you can bolt up your current exhaust
-Headers sometimes create heat problems with the starter
-Headers in place make it harder to get starter in and out
-Headers often have clearance issues with clutch linkages, crossmembers ect.
-Header gaskets have a reputation for leaking, be prepared to revisit you gaskets from time to time.
-Headers look cool when they aren't rusty. Coating them is advisable and an additional expense.
-You may enjoy both an increase in HP and Gas mileage with the headers
-With headers you will need to have a dual exhaust fabricated, a good idea with either stock manifolds or Headers.

I nearly put in headers into my 2wd 390 but stopped short. I did remove a set in a junkyard truck (probably Hedman brand). I needed to use a scissor jack between the frame and the engine block (motor mount to perch un-bolted) to tilt the block up and over a bit to get header in between block and steering gear. About ten years ago on this forum, Jowilker, had two sixties era 352 FE trucks. One had a 4V and Hooker headers, and another was a stock setup. He was reporting at the time that the header route wasn't worth the trouble. I still see him posting on the FE forum.

 

That's pretty trick, i like that.

 

And john ( jowilker ) is sttill running those ( Headers ) Today...................................


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montana_highboy

Thanks for the comment ! Cool....