Ebay offers VEVOR 8pc Exhaust Pipe Stretcher Expander Tool 1-5/8" to 4-1/4" Wrench Expander for $65.89 (reg $80) with free shipping.

Product Description:
The exhaust pipe expander stretcher tool set is a convenient, inexpensive alternative to hydraulic pipe expanders. It comes in a plastic storage case for easy carrying and classification. Collet sets expand pipes from 1-5/18" to 4-1/4", so they can be used on most vehicles.

• Exhaust Pipe Stretcher Kit
• Wide Expanding Range
• Easy to Operate
• Heavy-duty Construction
• Convenient Storage