Less substantial, but to my understanding, a better fit.  All I really know is that I used two of the thicker ones and both leaked.  The thinner one has now been in for several years, with no puddles. 

Karl Wolz
Sent from my electronic umbilicus

On Jun 14, 2013, at 7:57 PM, Alistair Bell <albell@SHAW.CA> wrote:

> I agree, use the thicker (and heavier one). GW sells an expensive thick one that by some accounts is the best. I have had 2, one purchased separately and one with a Victor Reinze kit. The latter was thinner and less substantial.
> 
> Drive in carefully, one can de-burr case hole a little with de-burring tool to remove sharp edge. Bottom the seal out, use old seal between hammer and new seal.
> 
> alistair
> 
> 
> On 2013-06-14, at 6:54 PM, Jeff Lincoln wrote:
> 
>> Karl - that's what I installed the thicker one. I did counter sink it
>> though per go ole' Boston Bob's video.
>> 
>> Why the thinner one? I picked the thicker one based on a big write up on
>> the Go Westy site .
>> 
>> 
>> --
>> Thanks,
>> 
>> Jeff
>> '85 GL (Gertie)
>> '78 Bus (Melissa) Patty's Bus