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Old 11-13-2011, 08:43 PM
Impala5967 Impala5967 is offline
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BBC 049 Heads on 489-496 BBC with ISKY238/248 upper HYD roller cam kit

Hello all, Building a 489-496 BBC in planning stages. Will be in '68 Vette (orig 427 3x2 car) TH400 auto (will get stall to match engine) 3.70 gears. Street very little strip maybe 2-3x year. Want to run on pump gas figure 10-10.2:1 CR. Want to retian stock look of Original 427.
the build (have Isky topend kit, 454 4 bolt block, 4.25" 4340 crank, 6.385" Eagle ESP H rods, NO PISTONS yet or heads )
-ISKY 238/248 @ 0.050" 578i 608e
-ISKY 8005-A springs
---135# set pressure @ 1.875" install hieght
---400# / in.
---1.530" OD
---1.100" coil bind
-ISKY 3607-ST retainer
--7 degrees
--.530" OD
--.730" ID
-ISKY VL-3/8 locks
--1 groove, 5.5mm Valve Stem
- ISKY puchrods 203-96 Minus .650
--7.650" i
--8.600" e
-ISKY Hyd roller lifters 3970-HYRT
-Corvette 3x2 dual plane intake 3 Holley 2 barrel carbs.
-Run Headers or Side pipes with headers.
-Have Comp cam SS full roller rockers.

Plan to go with GM 049 casting that I am assuming will need rebuild. Plan is to upgrade to 2.19i 1.88e, Home port and polish and install ISKY springs. Figure Bare castings and possible some or all guide replace ment. I do NOT know the condition of the Valve guides yet.
I am assuming I will need NEW Valves.
1) What are my options with valves stock 3/8 or 11/32 stems if some or all guides need to be replaced is it worth it to update to 11/32 stems given data above ? (I am not sure if worth it I assume new locks, and not sure what else will not work with 11/32 valve)
2) I am not sure what stock install height is of springs are on 049 heads with the Install hight of ISKY Springs 1.875" will it work ? DO I need to consider longer valves or machine heads or shims or combo ? Which is the best option. Will one or combo of options work better given I have the pushrods lengths.
3) Is thre any good calculators out there to help figure this out becuse I may have to cut the heads to get desired CR ?
4) What are good valves to consider ? What are Ferrea Valves?
5) What are the best updates to 049 heads to make POWER and FLOW?

I will be getting the heads tomorrow and will take them apart and clean up. I will take them into the Machinest and get his take (get them checked out)

This kit is nice but has me working backwards a little.
Good thing this is a winter project.
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