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Discussion Starter #1
If you were building a pump gas blower engine for a lake boat with 6lbs boost expected
B&M mega 420, lee chiller, dual 850 holley boost ref.
MK IV 454 block bored .40 over.
2 bolt now, convert to 4 bolt.?
rods I beam or H beam?
aluminum heads. brand and size?
pistons?
Compression goals? etc.
semi budget....
What would you build
 

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It would help a lot if we knew your budget. If it's $5000 the parts would be different than if it's $15000. Give us a starting point. As an example, I'm building a blown 540, probably gonna cost in excess of $18000 and I have some of the parts already. TJ
 

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If you were building a pump gas blower engine for a lake boat with 6lbs boost expected
B&M mega 420, lee chiller, dual 850 holley boost ref.
MK IV 454 block bored .40 over.
2 bolt now, convert to 4 bolt.?
rods I beam or H beam?
aluminum heads. brand and size?
pistons?
Compression goals? etc.
semi budget....
What would you build
I would go 4 bolt mains, with studs. IMO you have a potential 750-850HP combo with the right parts on pump gas. 2 bolt mains isnt what i would want there.

I would go H Beam. (An H beam really doesnt cost much more than an i beam)

I would go with a quality blower piston with upgraded pins.


I have a pair of 468ci, with B&M 420's, 6lbs of boost, that made 804HP at 6200 on pump gas. They have been in my boat for 2 summers running great in this form.

Mine are
MARK IV blocks
4 bolt mains with ARP stud kit
GM 4'' steel crank
Manley H beam rods with ARP 2000 bolts
JE flat top blower pistons
older Dart 308 Race series alum heads with some port work
236/245 .630 lift, 114LSA Hyd Rollers
Morel 4603 lifters
Isky springs.
Twin 850 Holleys.
B&M 420's non intercooled
MSD distributor with Crane ignition box. Timing locked at 32.
 

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Discussion Starter #7
I would go 4 bolt mains, with studs. IMO you have a potential 750-850HP combo with the right parts on pump gas. 2 bolt mains isnt what i would want there.

I would go H Beam. (An H beam really doesnt cost much more than an i beam)

I would go with a quality blower piston with upgraded pins.


I have a pair of 468ci, with B&M 420's, 6lbs of boost, that made 804HP at 6200 on pump gas. They have been in my boat for 2 summers running great in this form.

Mine are
MARK IV blocks
4 bolt mains with ARP stud kit
GM 4'' steel crank
Manley H beam rods with ARP 2000 bolts
JE flat top blower pistons
older Dart 308 Race series alum heads with some port work
236/245 .630 lift, 114LSA Hyd Rollers
Morel 4603 lifters
Isky springs.
Twin 850 Holleys.
B&M 420's non intercooled
MSD distributor with Crane ignition box. Timing locked at 32.
Cool thanks
 
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