With the firing orders of the H.O. (13726548)and the older pre 83 firing order (15426378)isn't the crank throw different and its not just the cam? Someone on here toldme in another thread that they are the same and it just seems impossible to me that they can be. The cam and the crank throw have to correspond to make the motor run correctly right.

 

your wrong unfortunately

 

just the cam is different

 

the crack is exactly the same.

if you look at the firing order itself, its kinda self explainatory... the order ov events just swaps the compression stroke for the exhaust stroke, via cam timing

13726548
15426378

see the 4 cylinders that swap locations in the firing order are phased exactly 180° through the order.

 

Yes I knew about the 4 cylinders that are swapped. It just didn't sound right. Thanks guys, just wanted other opinions.

Another question then, why is it that after I do the roller conversion that I can't use regualr roller cams with the spider plate and dogbones and have to use a small base base cams? I would love to be able to use the trick flow stage 1 cam but I don't want to have to spend over $500 for the linked lifters.

 

because the old block castings didnt have the bosses to bolt the spyder down

 

Thats why the conversion kit comes with the bolts for it that you have to drill and tap the holes.

This kit
http://store.summitracing.com/partde...p;autoview=sku

 

adder did that 347 job kick your ****?

 

This is only 1/2 true AdderMk2. The lifter bores are also shorter.

 

Because of the shorter lifter bore, to use the stockspider style of rollersyou have to use a small base cicle cam. Small base circle cams are junk because there is allot of deflection due to small base, and becuase they are Ductile Iron the deflection can cause them to break. It is much smarteruse a large base circle cam with link bar lifters. Doing it right once is cheaper than doing it twice.

There is a cheaper way out though, there is nothing special about that 83 block, why not get a usedroller block. They aredime a dozen,they can be had for $100 for the smart shopper.