Next steps for stage II -103

[6165hd]

Well, Many have been down this road before.....

I'm looking to take my current stage II 103 to the next step. I am interested in getting either the SE 103 heads or to port my stock heads.

Can I go with my current set up of the 255 cams, same 103 bore/flathead pistons? Adding in perfect fit push rods with the new heads??? With this on the plate, will it provide a noticeable difference in either torq or horsepower???

I love the trottle response from the 255s, so switching to another cam, Im afraid of missing that thrust at the get go.

Thanks,

Joe

[Mike]

I've been reviewing our 103 build dyno charts lately and have noticed that even with 255 cams, these motors benefit from porting. The trick is marrying an exhaust the compliments the low end tq (2-3K) of these cams (the very reason we typically select them for specific builds). But none have shown great PEAK numbers when compared to motors with more cam (similar to 258s). Motors with more cam, when marryed to a D&D Boarzilla exhaust, ported heads and 10.5-10.8 compression have shown very good gains from 2.25 rpm and on. If an owner were willing to sacrifice some tq from 1750- 2250, they'll realize MUCH more power.

So porting the stock heads would be the best next step. The 103/103+ heads have not given good performance gains to justify the cost. The new MVA heads would be a good option but have too big of valves to really compliment the 255 cams (simply will not utilize them). With a cam change, these would be a good option. I agree with your assesment of the low end grunt of the 255's. So this is why we come to porting the stock heads. Problem here is that to really get a benifit worth the cost, full porting is required. Partial porting (Baisley SuperStock @ $950.00) has not shown great gains with the 255's. Pro-Street porting ($1950.00) has shown gains across the board when used with 255's. Again, these gains above 4k will not be great as the cams shut down flow at higher rpms, yet suprisingly, we still see good gains. A cam change would take better advantage of the heads but risk loosing tq between 2-2.5K.

As always, the exhaust plays a BIG part especially with ported heads.

[6165hd]

Thanks Mike great information and feedback. I am starting to get the picture,
With the 255's being limited, thinking about switching to another cam to justify better performance through the rpm range ,and to really take advantage of porting.

[Mike]

So long as you are willing to downshift, the performance will be greater.