Small Block Ford, Pro Comp Heads, Guides

[Big bald guy]

Anybody have a part number for a direct fit for their .5055 OD guide?

[Walter R. Malik]

Personally, whenever I get a set of those in here to fix ... I ream the guide holes to Brodix size and use those guides.

Customer agrees to pay for it or just take them somewhere else.

[PRH]

I usually just put liners in them.

[resurrectionjoe]

P.E.P. has some that should work

B350+3 is .342 x .505 x 2.125

B350+5 is .342 x .507 x 2.125

It been years since I've worked on a set of those but I recall using the B350+5 and lightly honing the head,

because the bore finish was way rough and they didn't have as much press fit as I'd prefer to have.

[cgarb]

Do you think the problem around the Import guides are the guides themselves or the poor valve seat work that causes them to wear? Is it material issues or geometry that is the culprit? Just asking because I did a set of Import castings for my stepbrothers 355 and the valve job was terrible. I can see why people have problems with trying to bolt them on. I a set of Assault heads bare and ported them, did the valve seat work and adjusted the guideplates to get the best geometry out of the rockers I could get. It runs fairly good for what it is. Its a 355 that's 12.5-1 in a 26/2700lbs car and it went a 6.32 at 108 1st time out.

[PRH]

I’ve heard that the guide material has improved, but I don’t have any experience to back that up.

I’ve seen ProComp bb Mopar heads that came off a puller where several of the intake guides were just wasted........ in what I consider pretty low run time.
Like .009” clearance wasted.
None of the guides were even remotely good, but some were clearly way worse than others.
However....... the seats weren’t nearly as bad as the guides, and even came in pretty easily after new guides were installed.

For me, the bottom line at this point is, i haven’t had enough used ones come in yet to say definitively one way or the other if it’s a guide or seat problem.

The new ones I’ve had go through the shop within the last year or two have had pretty decent seat concentricity though.