moper
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- Nov 15, 2010
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A few comments on if this was mine to build... These are all my opinions based on my experiences with them.
Building bigger will cost no more than building smaller. IMO if you want a 451, just build a 446 (stock 440 with .030 overbore) as they will be cheaper overall to do.
You can use various parts to get the displacement up to 512. My advice would be avoid the 4.15 crank and RB rod. Stick with the 4.25 or 3.915 with the B rod. They will cost the same to build, and the 4.25 stroke will give you a feelable torque boost over the 3.75 or 3.915.
Source is a good place for a kit. Not kit should be ordered balanced by them. No kit should be assumed to be 100% ready to drop in as delievered. Rods will neeed attention at least in terms of serious inspection. I always budget the rods being resized. The pin ends need to be honed to fit - not sanded by hand as Source suggests. The crank needs to be carefully measured and a decision made as to if it's good enough as is or need turning to remove the taper that it will always have. Also check the clearances carefully by measuring - plastigge is not accurate enough to use when working with all aftermarket parts. Most of the kits I've used were tight - almost too tight. B wedge kits will need the rod bearings chamfered before mock up.I build to take advantage of quench. I would be building this with dished pistons and bringing the piston to where I get a minimum piston to head distance of .035 when using a .039 gasket.
The only heads that have straight plugs are the Stealth heads from 'Source. All the Edelbrocks are the same aside from the chamber volume and open or closed. The head choice depends on displacement and pistons used. All will need to go to a good performance head shop to be checked and corrected prior to running. Some may need parts to complete them, or parts replaced due to poor quality and inadequate performance with the cam used.
I would not use an MP cam unless it was forced on me. Ther are MUCH better designs, not necessarilly because they are split pattern, just because they are better camshafts. MP are made as total junk these days. The designs were good when the major grinders were not focussing on Mopar stuff. That was in the 1980s. The heads you're looking at are modern. The pistons are modern. The fuel used is modern. So why would you want to run a camshaft designed with you could get 110 leaded from the pump for $.60/gallon? The cam you will want will be larger than what you're looking at currently. Big engines need a little more static compression, and bigger engines need larger camshafts. Small camshafts can cause problems in big motors on pump gas.
You will also want to use an appropriately sized carburetor. Exhaust manifolds are not a big deal with the Stealths. Headers will be better on any larger engine.
Building bigger will cost no more than building smaller. IMO if you want a 451, just build a 446 (stock 440 with .030 overbore) as they will be cheaper overall to do.
You can use various parts to get the displacement up to 512. My advice would be avoid the 4.15 crank and RB rod. Stick with the 4.25 or 3.915 with the B rod. They will cost the same to build, and the 4.25 stroke will give you a feelable torque boost over the 3.75 or 3.915.
Source is a good place for a kit. Not kit should be ordered balanced by them. No kit should be assumed to be 100% ready to drop in as delievered. Rods will neeed attention at least in terms of serious inspection. I always budget the rods being resized. The pin ends need to be honed to fit - not sanded by hand as Source suggests. The crank needs to be carefully measured and a decision made as to if it's good enough as is or need turning to remove the taper that it will always have. Also check the clearances carefully by measuring - plastigge is not accurate enough to use when working with all aftermarket parts. Most of the kits I've used were tight - almost too tight. B wedge kits will need the rod bearings chamfered before mock up.I build to take advantage of quench. I would be building this with dished pistons and bringing the piston to where I get a minimum piston to head distance of .035 when using a .039 gasket.
The only heads that have straight plugs are the Stealth heads from 'Source. All the Edelbrocks are the same aside from the chamber volume and open or closed. The head choice depends on displacement and pistons used. All will need to go to a good performance head shop to be checked and corrected prior to running. Some may need parts to complete them, or parts replaced due to poor quality and inadequate performance with the cam used.
I would not use an MP cam unless it was forced on me. Ther are MUCH better designs, not necessarilly because they are split pattern, just because they are better camshafts. MP are made as total junk these days. The designs were good when the major grinders were not focussing on Mopar stuff. That was in the 1980s. The heads you're looking at are modern. The pistons are modern. The fuel used is modern. So why would you want to run a camshaft designed with you could get 110 leaded from the pump for $.60/gallon? The cam you will want will be larger than what you're looking at currently. Big engines need a little more static compression, and bigger engines need larger camshafts. Small camshafts can cause problems in big motors on pump gas.
You will also want to use an appropriately sized carburetor. Exhaust manifolds are not a big deal with the Stealths. Headers will be better on any larger engine.
