351w build

[410]

alright i need some ideas im going to rebuild a 351 i have out of a 89 f250 and need advice i plan on doing this on a tight budget im going to use a 600-750 cfm carb aftermarket heads or gt-40p if i can findem i have a zf-5 tranny that im gonna use with it i know it will need to be bored so how much is too much 10-40 over and what rpm range should i go with idle-6000m or 1500-6500 and a good rearend ratio i have 308s in a 8.8 it will be put in a 90 f150 and used on the street and maybe a trip or two at the dragstrip no towing and ideas or opinions would be helpful

[Conanski]

With any heads smaller than AFR185's on this motor a cam that makes power above 5000rpm is a mismatch.. the heads don't flow enough to keep up with the motor so power drops. So you want one that does 0-4500 or 5000rpm at most, the Comp Cams 35-238-3 is a good fit.
Don't bore the block any more than necessary.. the machine shop will tell you what is needed, but there are more piston options for 0.030" so use that if possible. 3.08 gear isn't the greatest for a truck and since you have an OD tranny step up to 3.73 or 4.10. Here's a graph of what is possible with this combo, if you use more of a stock piston the compression ratio won't be this high so the output will be a bit lower. A 650cfm carb and small tube headers will also a better fit for a street motor.

[410]

thanks conanski idle-6000 is where ill build it on the pistons forged or hypereutectic i would like to get 9:00-1 to maybe 10:00-1 on the compression

[Conanski]

Unless you plan on adding gas or boost cast pistons are fine and I suggest you keep static CR around 9 to 9.5:1 to be pump gas friendly, stock pistons and the GT40p's will put it in this range.

[410]

do you happen too know anything about scat industries i found a complete rollimg assembly from them and was wongering if there any good its got a crank rod and main bearings rods pistons and rings

[Conanski]

Is that s stroker assembly? Scat does make good stuff but it isn't required to make power on this motor, the stock rotating assembly can handle well over 400+hp.

[4wheeling79]

Like conaski said scat does make good stuff and it is not really needed unless we are talking stroker. you could find a 3.85 cast crank relatively cheap use your stock 351 rods and 302 pistons to build a low buck 393 stroker. I going to guess you have an 80's block you could scope the junk yards for a 351w roller block and upgrade to a roller cam also.

[4wheeling79]

Like conaski said scat does make good stuff and it is not really needed unless we are talking stroker. you could find a 3.85 cast crank relatively cheap use your stock 351 rods and 302 pistons to build a low buck 393 stroker. I going to guess you have an 80's block you could scope the junk yards for a 351w roller block and upgrade to a roller cam also.

[camccardell]

would you need to up the size of the injectors with a 393 stroker?

[Conanski]

IMO a stroker is a complete waste without much better heads, and that puts the motors fuel requirements at about double what the stock injectors and computer can handle.

[cadunkle]

i would do a mild port cleanup on the stock heads and run a Comp XE268 cam. Shoot for 9.5:1 with your pistons and plan on running 91+ octane. I'd run hypers if you are sure you'll stay out of detonation, if not cast will be fine. Go with lowest overbore that'll clean up and has pistons you want to run. Boring doesn't get you any appreciable increase in displacement or HP. Change your axle ratio to a 3.55:1 if MPG is your concern, 4.10 if you wanna play. If you stay with the 3:1 I'd go with maybe a Comp XE262 cam. Run either an Edel RPM or Weiand Stealth.

Low budget and stroker don't go together, you'd just be spending extra money to move your powerband lower given stock heads. See if you can get by just polishing the crank, if not just cut it, it'll be fine.

[camccardell]

not trying to hijack the thread here, but I am compemplating a 393 stroker, or 387 since I am not boring .030 over.
I am going for low rpm grunt, and offroad fun. On that note, do I still need bigger injectors? 32# sound good? How about a fuel pressure regulator? I ask because I'm used to turing a screw for more fuel, not changing injectors, programming and so on.
What about fuel pumps? New in tank units for both, or is there an in-line add in fuel pump.
I have a tweecer, so programing should be straightforward enough.
How about the cam? Stock 95 roller cam good enough since I want low rpms?

And finally, what about the stock heads.. Yeah I know they suck. Would a port job take care of it, or do I need to pony up some serious coin.

I ask all of this because I am debating converting to diesel or going this route.

[4wheeling79]

For the injectors it depends on which way you go. Stock cam, stock heads intank pumps will be fine use 24lb injectors start at 40psi fuel pressure work from there.
Know the other way is to take full advantage of the extra cubes. The stock heads you are talking about i'm going to guess are E7's you are right they suck nothing can help them. There is no way i would use them and if you do your motor will suffer. And the stock cam will top it off.
Save your money and do it right get a good set of heads and much better roller cam. Check the mustang web sights there is always some one looking to get rid of theirs at a good price. Then you could use some 30lb injectors

[410]

no its not a stroker set thought about it the blocks out of a 89 and its going to be carbed dont like efi so far with just the parts for the motor itself i would have 2 grand in it without the heads and machine work some budget im doing this mainly for a play truck and everyday running i was going about 30 over nothing extreme will do that with the 5.0 ho

[4wheeling79]

so you are going to buy a stock rotating assemble Y? Like i was saying you could build a 393 very cheap and very reliable. I found 3.85 stroke cranks for less than 300 dollars yesterday and 302 pistons are every where and you already have the rods. if you have just 2k set a side for the motor this is very doable. You just need to find a set of good heads. check dfwstangs, stangnet, and corralnet. you can find what you need on these classifides if you keep looking