what aftermarket heads are out there for and early 90s 351w

 

AFR's are the best. AFR 165 heads will bolt on a stock engine no worries, the 185's have 2.02 intakes and usually require fly cutting the stock pistons if you're running a cam with much lift. Aftermarket pistons are usually good to go with bigger valves.

Ford Racing X303 heads are a good option if you want to keep the pedestal mount rockers, etc..

 

What exactly are you doing? Are you upgrading an EFI motor for a truck or something else? What are you power goals? How much money you got to spend? There are loads of heads to pick from but heads should not be your first upgrade on this motor.

 

i am going to do a block out build. stripping down a motor and building it to have as much torque and power as i can with my stock tranny. so i was just wondering what was out there for these motors. i am going to put a high lift cam in and possibly bore it over.

 

Like Conaski said...it depends on budget. I managed to get a set of gt40 heads in re-built condition for about 500. It should be a mild improvement over the E7's. To get to the really good stuff, I think your looking at 900-1300 bucks for a set of aftermarket heads.

 

You can get near 300hp and 400ft/lbs TQ out of the stock heads and intake, and over 300hp with GT40 heads or some port work on the stock heads, the key to this is a high flow exhaust and the right cam. However, once you get into the really good heads like the AFR185's, if you also put a better intake on the motor it will flow more air that the injectors can fuel, and this is where it gets expensive. You need a mass air conversion and a tuner to calibrate the motor, along with all the other parts you are already buying. If you go carb it simplifies this some, but if you have an EEC controlled tranny you're just substituting 1 problem and expense for another.

 

let me tell you exactly what i am going to start with, then mabye you can make some suggestions as to what i should do to get the most bang for my buck. i dont want to mess with the injectors cause its way over my head price-wise. i have a 1990 f-250, i think its a heavy duty cause its got the bigger hubs and the gvw is 8600 i think?. it is a 5-speed i dont know the tranny numbers. i would like to stay with the efi just cause its easier to deal with where i live cause the weather changes so much, i dont want to deal with a carburetor. what cam should i use ? i would like a choppy idle just for the hell of it. also i was looking at gt40 heads and porting them.

 

Paul and I are on opposite sides of the fence when it comes to heads. I think aftermarket heads should be among the first parts you buy if you're serious about making power. 300hp sounds strong for a 302 (unless we're talking rwhp, then it's healthy for a 351...). 1hp/c.i. has always been a performance benchmark and with aftermarket heads it's almost a given. At least on a carbed engine. I know EFI has some limitations but to get the most out of it you'd need to have the computer reprogrammed for a new cam/exhaust anyway, so you might as well go whole hog while the engine is out of the vehicle.

I absolutely agree you need to consider the entire build and put together a combination that achieves what you want - maximum performance. A mismatched combo will leave you frustrated and scratching your head trying to figure out where your lost ponies are.

That being said, talk to most engine builders and they'll tell you factory cast iron Ford heads are junk. Even with porting and bigger valves you're leaving at least 40 hp on the table vs. a pair of AFR165's. I've heard the same thing from two guys who've built hundreds of racing engines and done thousands of dyno pulls - Kim Barr here in Dallas and Joe Sherman. I suppose building a 600hp (or 800hp) naturally-aspirated non-nitrous SBF and building a 350-400hp truck engine isn't the same, though other than compression and cam selection - and ensuring the engine can safely turn 8,000rpm - the principle isn't different.

Spending $500 for a mild improvement (i.e. GT-40 heads) when you could spend $1,200 for a 50-60hp improvement seems like a no-brainer to me. Buy some good heads first and the result from every other modification is magnified.

Anyway, I recommend you find a good local engine builder and work with him to find the best combo for what you've got and where you want to go. I'm building up a 351w right now and I'll have some dyno numbers in a couple of weeks. After spending ~$600 on parts/labor and many hours porting the heads I ended up buying a pair of X303 heads anyway. I don't think the cam I'm running is EFI compatible (Comp XE250) but I'll post the dyno results when every thing's buttoned up FWIW. I'm hoping for 360-375hp at the crank, so I reckon we'll see.

 

OK.. if you want to stay with the stock EFI system you have to get the idea of a choppy idle out of your head right now.. 'cause it's not gonna happen. The only cams that will work with the computer are the ones that provide a solid vacuum signal, and this means you have to live with a smooth idle. One of the best cams I have found yet for the stock motor is the one I currently have, it'll provide lots more power across the powerband and work with the EFI. Nevemind all the other stuff I have in my sig line, I'm in the middle of building my 5.8 to about the same level as The Baron but I'm keeping EFI. The GT40 heads are a good upgrade for the 5.8, but don't sweat it if you don't get them yet, there's lots more power in the stock motor you haven't seen yet. You'll want to ditch the complete exhaust system on the truck as well, install longtubes and a nice 3" single or small duals..but don't get too carried away with the monster exhaust, you'll just make the motor soft at low rpms.

I wouldn't say I'm against changing heads on these motors, but on the 5.8 it's all too easy to make it outflow the stock injectors, and that opens a whole 'nother can of worms and expense. With the Tweecer I'm able to see realtime what the various sensors are doing on the motor, and my combo is all but maximizing the 19lb injectors. The heads I have are no better than stock E7's, so a set of untouched GT40s will stretch the 19 pounders for all they're worth, I'd suggest an adjustable FPR so you can bump the pressure a bit.

 

I wonder if my combo is close to maxing out the injectors.
88 Mustang 5.0HO 70mm MAF, 70mm TB, Explorer GT40 intake, E-303 cam, 1 5/8" shorty headers with two 2.5" high flow cats and 2 chambered Flowmastwers with turn downs. The heads are still stock, but this thing pulls hard from 2500 to 6000. For some reason, the factory 6250rpm rev limiter no longer works. I was acting out a bit in it the other day doing a burnout across the parking lot here at work and when I looked down, it was @ 7000rpm so I back off before the rods exited the block. The poor old engine has 163,000 hard miles on it, but runs strong as ever.
I may just get a set of 24lb injectors and a 93 Cobra ECM and see how it does.

 

i already have long tube headers and true dual 2.5" out the back so im good for the exhaust. i was looking at crane cams and comp cams the other day but didnt decide on one cause i hadnt decided what else im doing if, i just get gt40 or something mild and port them what would be my best value on a cam in your opinion. i was thinking about opening the intake some but unless i finally get my refund check i dont want to buy bigger injectors.

 

If you get GT40's don't touch them, they outflow the stock heads by a bit right off the shelf. If you do any porting work at all it should be on the exhaust side, or the lower intake to match the runners to the heads. I'm in the middle of refurbishing the 5.0 I have, and upon measuring the lower intake ports I found that they taper down to a size about 3-4mm smaller than the port opening in the E7TE heads. After I got over the shock the die grinder came out and they're well on thier way to matching the heads now.

As stated, the Crane 444232 is a David among Goliaths, it produces about the same power as cams with nearly 0.100" more valve lift.. on DesktopDyno. On the street in my truck the motor produces impressive TQ right from idle, and just keeps pulling as long as you keep your foot in it. There are a few other cams I have seen that look like they produce a bit more TQ and HP, but most are roller cams so you would need a '94+ block to utilize them.

 

i have never ported a set of heads myself, is there a book or somethiing that would kinda walk me through it if i decide to port the exhaust. also im having trouble finding a block that came from my era truck, would and earlier of perhaps a later year block work, could i use a 94+ block cause i've found several of them. if you have any other suggestions for a rookie builder pleeaase let me know.

 

oh yeah where is a good place to buy this stuff cause the shop around me switched owners and cant get a lot of stuff. besides i dont like dealling with morons

 

Summit Racing - High Performance Car and Truck Parts | 800-230-3030