6 bolt block 7 bolt head build questions

[DSMjunkieNH]

hey guys been on here a lot and got my short block all set with wiseco 8:5.1 compression 1400HD pistons with Manley Rods, all new oil pump, balance shaft, oil pan, new bearings, arp mains, 6 bolt stock crank. Was wondering I have a 7 bolt head that is currently at the shop. Im wondering is there anything bad about doing this swap. i already have the 7 bolt head drilled out for the 6 bolt head studs, is there any oil pressure problems when doing this swap? and Also im going to be pushing this to its limits shooting for a 10 sec daily what do you guys recommend I get done to my head and also what head gasket do you think I should be running. This is a touchy subject some people swear by cometic others by mls. Any inputs? also how straight forward is this 6 bolt block 7 bolt head swap? just keep all my 95 sensors or should I purchase a 6 bolt cas and wire it in to my 7 bolt head? thanks for any info

 

[evileclipse909]

It's a straight forward swap. Nothing special needs to be done. If you have the time and funds you'd benefit from having the head ported with a flow bench and get a good intake manifold. If you have link run a 1g cas, if not use your stock 7 bolt/2g sensors. I personally have had good luck with the cometic head gaskets.

 

[1990TSIAWDTALON]

I am doing the same thing with my 1G and my head is going to the shop this next week for a workover with new vavles, retainers, keepers, springs, guides, seals and having it plained just enough to make sure its perfectly flat so I am watching this thread also. I am using the original sensors on mine just swapping over to the 7 bolt intake since my car came with a 6 bolt intake on a 7 bolt head. I am also using the 6 bolt head studs so we will be reaming the head bolt holes to 12mm. I will be porting the intake to accept my 1990 TB and I am using a Cometic Head gasket on mine.

 

[TexasTurbo]

The oil pressure problems are caused by people not drilling the corner stud hole big enough. 1/2" drill bit is perfect sized to do the holes.

 

[1990TSIAWDTALON]

Which hole is that and a little more insite would help me a lot. Thx for the input.

 

[AllanL]

since you are reaming the head bolt holes to 12mm, maybe you are safe...

here're some more tips from Dale:

http://www.dsmtuners.com/forums/newbie-forum/341028-4g63t-head-oil-port-mod.html

http://www.dsmtuners.com/forums/cylinder-head-short-block/341885-oil-port-mod-2-4g63t.html

 

[BogusSVO]

Cometic is a trade name, and is a MLS head gasket.

Just be sure that both the head deck and Block deck have the proper finish to seal.

You have to use the head studs for the block you use, no way to use the 7 bolt head studs in a 6 bolt block with out modding the head bolt holes in the block to accept them, it is just simpler to ream out the head bolt holes in the head and run the bigger 6 bolt head stud.

Since the head studs are 12mm you will want the head bolt holes to be 13mm to allow for core shift and machining variance from production