FuzzyDiceRule

hey, ive got a couple questions, were starting to get the 306 for the RX7 back together...

first do GT40 heads require the bushings to fit a 7/16 stud to a 1/2 inch hole?

also, doed anyone know of a good online guide thing with all the torque specs and such? and the torque sequences

lastly, do i need to get new main bolts?

crusin92red5.0

i know there is a write up in the "tech articles" on the torque specs, but not the torque sequence. you'll need a haynes or chilton manuel for that or you might find in on the web.

and i wouldn't see a reason to change main bolts

projectresto83

Yes the Gt40's require bushings to downsize the holes to 7/16. Or you can get ARP head bolts that do the same but bushings and new stock bolts are just as good and cheaper.

FuzzyDiceRule

okay, also, can i be enlightened on the proper break in sequence for ze motor?

silver91gt

no they don't, the heads originally came from a 302 making the head bolt holes 7/16"
if they were off a 351 they would have 1/2" holes requiring the reducer washers, but gt-40's never came on a 351 in stock form.

woodsy

1993 lightnings

projectresto83

Many 351's had GT40's All GT40 iron heads require them because they are 1/2 studs.

FuzzyDiceRule

okay.... ill buy the bolts with the 1/2 inch thingy,

anyone care to enlighten on the break in when the swaps done



the way i think i was told was, run it for a while (30 mins?) to let the rings seat, check for leaks etc, then change the oil at 50, 1000, 3000 and then every 3k... cutting the filters to check for bearing failure


anyone care to correct me? or is this basically it?

projectresto83

http://store.summitracing.com/partde...5&autoview=sku
Those are arp's that come with the bushings.

Portmaster

Torque specs change with the bolts you use and the lube you use with the head bolts. You will need to put sealer on the head bolts on your 5.0 block as the head bolts go into the water jackets. I would absolutly stay away from the stock head bolts and go ARP. They have rolled threads instaed of cut and have much better clamping force and on 5.0s where it only has 4 bolts around each cylinder you need all the clamp you can get.

Once you figure out what head bolts you are going to use and what style lube sealer then start in the center of the head and work your way out in a criss cross fashion to the ends of the heads at about 20Ft lbs. Then do the same thing at 50 ft lbs and make the final torque to your specs. Go over each head twice for final torque.

If you didn't machine the block use the same main cap bolts that came out or go to ARP Bolt. If you plan on Studing the mains you need to have it line honed using the studs torque to spec. It will create cap distortion.