Well, I finished the short block of my 388 stroker motor and all the clearances look great. So I'm ready to put the heads on and check piston to valve clearance and valvetrain geometry. I pull out my Felpro 1003 head gaskets, (recommended by AFR for the 195 heads I bought), and the Felpro directions say to drill a 7/16" hole in the block between the center 2 cylinders on the exhaust side, where there's a similar cooling hole in the gasket. Of course, it says to do this before assembling the engine to avoid metal chip contamination The 1003 also has very small cooling holes between the outside cylinders on the intake side, where large holes exist in the block. Obviously restricting flow in this location.

I pulled out a standard Felpro head gasket which I've used successfully on other builds, and it has the same hole between the center cylinders on the exhaust side (where the 1003 gasket says to drill), but the gasket holes on between the outer cylinders on the intake side are much larger than the 1003.

So how important is it to drill this additional hole in the block? I'm already a bit concerned about the motor cooling, since it's .060 over bore. Can I get away without drilling the hole? Should I use the standard gasket (I'm running 10:1 compression) with the larger holes on the intake side? Thanks for any guidance

Jimbo

 

Anybody????

 

Sorry I can't answer your question but I have had good luck on www.chevytalk.com. There is a guy on there called grumpyvette that I bet could answer your question. Good luck!

 

Jimbo, I'm certainly no expert and probably nowhere near as experienced as you. I just completed my first top end rebuild with the installation of Edelbrock Performer heads on my sb.

I used Cometic head gaskets after exhaustive research, posts and copious amounts of beer! They were significantly more expensive than Felpro or others but fit extremely well and so far I haven't had any leaks.

Not sure if this helps or is even an option. Personally, I'd be pretty hesitant to drill into the block. But, like I said, I know just enough to be dangerous.

 

I used the same 1003 on a 355. I drilled the holes like the dirc said. do not drill head gasket bigger.turn engine upside down ,start small,grease drillbit,try to recover all chip.If AFR says use them then use them if thickness meets your CR goal.aluminum heads(new head ) are R/D for even cooling.follow AFR's recommendation.I have brodix track 1 at the time (12 years ago) they seamed the best.AFR's now out class mine.understand C-3 suck when it comes to cooling a performance engine.I struggled for years,to keep mine cool.Alot of money spent,then I bought a BE-COOL radiator. greatest money I ever spent 600.00 radiator/10,000engine. U won't be dissatisfied.Again money well spent.1003 were good. now I bought cometic .051, they were recommended buy borodix for my 406 app. 170.00 for pair ouch!

 

Thanks guys. I may sit on this for a few more days, and do some more research. I need to learn how the water flows through the block and heads. Then I can make an informed decision.

Jimbo

 

I just finished a 383 with 195's and cant believe you would need to drill ANY hole in the block. I'd be careful about that one.

I used thinner Victor Rienz gasket.

After some digging, it looks like that is a good mod if you're willing to do it.

 

Last night I took parts to my builder.We talked about 1003. He uses them on all street, circle track iron head/and there used for 195's.He has them on a12.5cr afr220 or 230 406 597HP Dyno.Must be his choice,he has dozen sets hanging on wall.Showed me three 350 blocks,early blocks no hole,need to modify.later block had about 3/4'' from factory.I striped thirty of those early blocks as a kid! Center Exaust were mostly white,burnt,sunken into head,heads cracked between valves/all kinds of problems.I think GM corrected the problem.I wouldn't worry about doing it now,use a vacuum,turn motor upside down.Drill hole to size that dirc. say.It's not going to hurt if every little bit isn't recoverd.Drilling castiron is more powder than chips.I wouldn't inlarge any holes in head gasket,there r/d for even,balanced flow. hope this helps.

 

I use Fel Pro 1010 gaskets with Aluminum heads, they have a Copper "fire ring" where the 1003 has a Stainless Steel one and can brinnel the heads (my 2 cents on the subject.)