I have a fresh, complete 4.1 stroker with TA alum heads, and another 4.1 also with a 3.625" stroke which is a short block and cam.
Both have 2 steel center caps.
The bigger bore 4.1 stroker will run high 9's all day at 16-18 PSI boost with the appropriate supporting parts.
The 3.8 stroker build are only done to customer specs since the bigger bore 4.1 provides much better low end/mid-range power at relative low boost - more air in, more HP produced!