ENGINE BUILDER SAYS i BETTER DO THIS!!

[RIXX93GT]

Okay I was talking to my engine builder and he advises me to go to 1/2" head bolts on my block for my 347 build up. It is going to be a 10.25:1 compression NA moter with AFR185's and full forged rotating assembly with an FTI custom cam. What is everyones opinion on if this is really necessary or is it just good and wise insurance?

 

[Michael Yount]

Depends on your definition of "necessary". Can the engine be assembled and run with the smaller head bolts? Yes - so it's not "necessary". Does it make sense to upgrade to the larger size - I think so.

 

[mike93lx]

doesn't seem like a cheap build up, so why take the chance? the cost will be minimal compared to buying new smaller bolts.

 

[Sofgwhat]

How much is this going to cost you?

 

[onefaststang]

In order tp put the larger bolts in you must drill and tap. The factory 302 production blocks don't have enough meat around the head bolts to do this. You will actually weaken the block.

Not recomended.

7/16th studs are plenty strong for whatever you can throw at them.

 

[matty50racer]

I say stay with 7/16 studs. I am using them on my 500 horse 11.5:1 331 and wouldn't use anything else.

 

[runningmole]

You'll need 1/2" spacers or whatever they're called for those AFR185s. They're drilled for 1/2, not 7/16 like the 165s

 

[TIMMY2734]

Im with the crowd on this one. The 7/16" studs will be plenty strong for your build up.

 

[TheUser]

i don't know the technical things, but I know the arp studs are supposed to be real strong. That's what I put on my mine...$100, but I think it was worth it.

 

[EMW150]

In order tp put the larger bolts in you must drill and tap. The factory 302 production blocks don't have enough meat around the head bolts to do this. You will actually weaken the block.

Not recomended.

7/16th studs are plenty strong for whatever you can throw at them.

I agree 100 percent.

 

[Rick 91GT]

In order tp put the larger bolts in you must drill and tap. The factory 302 production blocks don't have enough meat around the head bolts to do this. You will actually weaken the block.

Not recomended.

7/16th studs are plenty strong for whatever you can throw at them.

Exactly....just use the 7/16" ARP studs and 1/2"-> 7/16" stepped washers. If you need a set of washers let me know, I have a brand new set of ARP's I didn't need for a motor, I'll let them go for a good price.

 

[Michael Yount]

Thanks guys I'm learning something here too - do the 351 blocks use the 7/16" bolts or the 1/2"? I've thought they used the larger bolts; if so, are those blocks cast differently/with extra meat in the areas around threaded holes? Is that part of what the extra deck height buys you?

 

[Ranchero5.0]

351's are much beefier and come with 1/2" threads. I'm running the 7/16 ARP's and stepped washers. Buddy's block cracked where the builder (professional) drilled and tapped it for 1/2" bolts. He was pissed when he tore it down and found that.

Jamie

 

[perkys stang]

yeah.. I would stick with the 7/16 for sure... The step washers work great

 

[1BAD89GT]

Same here stay with the 7/16 im ruuning the ARP's read sig.

 

[MUSTHAVE302]

Small block chevy's only use 7/16", and plenty of guys run wild 400 inch combo's with high compression, and no problems. The difference is SBC's have 5 bolts per cylinder, while the SBF only has the 4. You still shouldn't have any problems. I agree with the problems of drilling out the 7/16 for 1/2 - not only could it be too weak, it isn't the easiest thing in the world to make sure those holes are drilled and tapped perfectly straight. All you need is to have a crookedly (if thats a word) tapped whole and the stud is angled 10 degrees. Then you wouldn't even be able to drop the head on . . .

 

[Smokedawg]

I am running the 7/16 with arps on mine and no probs..

 

[RIXX93GT]

Well I dropped off the moter tonight and he is still recommending the 1/2" head bolts. I know this guy well and he has a great rep. Does anyone think it is a good idea or should I just say no thanks. Its not that much more money to have it done.

 

[Michael Yount]

I would have a talk with him and tell him you've got reputable builders here telling you that the block doesn't have enough meat to be drilling the holes larger and see how he responds.

 

[onefaststang]

I would have a talk with him and tell him you've got reputable builders here telling you that the block doesn't have enough meat to be drilling the holes larger and see how he responds.