What type of adapter? mounting, electrical, hose? Where did you purchase? Have you contacted their support ? Ifr it was GRP then contact Greg he's great with sales support. I just looked at his offering and it appears to contain adapters.

This claims to be compatible with MOST applications.

The 340LPH E85-Compatible High Flow In-Tank fuel pump includes a wiring harness, pre filter, internal fuel hose, clamps, end cap and rubber buffer sleeve. Every AEM 340LPH E85-Compatible Fuel Pump is tested to flow 340 lph at 40 PSI before it is packaged for sale.

• Tested and compatible with ethanol fuels up to E100, methanol fuels up to M100 and all types of gasoline
• Designed for high output naturally aspirated and forced induction EFI vehicles
• In tank design
• Each pump is tested to flow 340 lph @ 40 PSI
• 39mm diameter fits most applications
• Includes pre filter, hose, clamps, flying lead, end cap and rubber buffer sleeve

https://www.lotustalk.com/threads/anyone-install-the-aem-340-lph-fuel-pump.552715/

 

No. The problem is in tank fitting. It doesn't fit. The stock yes. This one needs adaption of in tank fuel. In order to stay fix. Must be an adaptor. Should be easy,piece of plastic. But I can't find. And the site claims it fits perfectly...