Silver Sport Transmissions has aluminum bellhousings or adapter plates for a variety of engine and transmission combinations including the full TREMEC line of 5 and 6 speed transmissions. Will you be converting to an LS or LT engine? SST's EZ-LS and EZ-LT conversion kits have everything you need to complete the job, including our stronger than stock 621 GM bellhousing with the proper LS or LT bolt pattern.