bobbyboura

I have a 68 289 that im rebuilding for my 88 mustang . I wanted to know if this setup would be worth putting together . I have a flat tappet cam and lifters that are simular to specs of a 351 windsor all comp cams. Dish top pistons keith blacks I think . I have a Edelbrok perfpormer 289 intake with four barrel performer 650 . I also had the heads prted and pollished a couple years ago . Would the pistons raise the c.i. i was curruious . Also I would be running a c-4 trans with the engine . I was woundering would this setup produce power simular or better than a 5.0

my77stang

all other things being equal, a 289 is hands down better than a 302 any day of the week.

????? that doesnt make much sense, and we need numbers.

your dished pistons are gonna net you terrible compression. I have flat tops in my 289 with 4 valve reliefs , the block is zero decked, and im using early 351w heads that have been milled. this combination nets about 10.0:1 maybe a tiny bit less like 9.8 or 9.9 or something.

the performer intake will be fine for low end power, but the 650 is too much carb for you without question. you need no more than 600 cfm, and a 570-575 would be even better.

mjr46

yeah but before that is a solid fact I would do away with the smaller rod bolts that 289 rods were equipped with which was a major reason for faliure when reving over 5000

67mustang302

The stock 289 rod bolts are a joke, but I think he put the most badass ARP ones in his 289 he just built. And yeah, dish pistons in a 302 is gonna be nothing for compression. I have unmilled AFR heads with a stock deck height 302 and 2 valve reliif flat tops and I'm only at a bit under 9.5:1 static.

my77stang

FYI mjr46,

the 302 shares the same puny 5/16 rod bolts yet have a shorter rod and longer stroke which equals a terrible rod length/stroke ratio. in their stock form with the crappy bolts, a 289 will safely outrev a 302 with its crappy bolts. hell even ford knew this, because when they made the BOSS 302 they had to use the 289 HiPo rods because the 302 rods are just too damn short (and the HiPo rods have thicker big ends and 3/8 bolts)

there are two upgrades that EVERY 289 / 302 rebuild should get.....
1) upgraded arp bolts - use 5/16, because drilling a stock rod for a 3/8 bolt weakens the rods around the bolt and defeats the purpose of the upgrade. there just isnt enough meat to do it. they have 3 varieties for stock rods, standard arp, wave-loc arp, and the pro series wave-loc arps. the first two cost about 55 bucks a set, the 3rd cost about 95 bucks a set. when i did my 289 rods, i polished them, used the 100.00 bolts, and then had the rotating assembly balanced.

2) upgrade the oil pump driveshaft. the stock units are terrible, and occasionally twist under normal conditions. upgraded arp pieces are like 20 bucks and should be considered some of the best money spent on a rebuild.

take a look at the finished product....