I am looking at getting a either SLP siamese or AS&M. If there isn't much of a difference, the SLPs are a lot cheaper and I would go with them.

Both are untouched and would be new condition.

 

I got some SLP's a couple months ago and they are cheap yes. however they are really rough inside and I doubt if they are any larger than the stock runners from the factory. From what I understand, SLP has really let their casting quality slide.

However if you were planning to port them or extrude hone or something then the SLP's have lots of material to take them to very large internal volume.

 

I have the SLP's. IIRC the runner ports are 1.44-1.48ish in diameter which is stock runner diameter. I had to buy some pricey tools to port the runners out to 1.68 all through each runner which is not easy. The extra cost of porting was close to 80 bucks plus the 20 hours needed to port and then polish them on the exterior. Bite the bullet and buy the ASM's. Out of the box they are ready to go.

 

That's what was wondering, they are expensive though.


Another question:
Does the plenum need to be opened up to match the AS&M runners too?

 

I have SLP's but after seeing a set from AS&M, I wish I had bought those instead. You will have to port match either set to the upper plenum.