Hormel Foods (HRL) had the highest return in April 1985 by a large-cap US stock, returning 106.1%.

ASSET	MONTH	% RETURN
Hormel Foods (HRL)	April 1985	106.15%
Unilever PLC ADR (UL)	April 1985	73.57%
BHP (BHP)	April 1985	27.71%
Shell PLC ADR (SHEL)	April 1985	20.63%
Bank of New York Mellon (BNY)	April 1985	18.93%
Franklin Resources (BEN)	April 1985	18.88%
Honeywell International (HON)	April 1985	17.11%
Valero Energy (VLO)	April 1985	15.59%
PNC Financial Services (PNC)	April 1985	15.48%
UnitedHealth (UNH)	April 1985	14.99%
Huntington Bancshares (HBAN)	April 1985	13.07%
Arthur J Gallagher (AJG)	April 1985	12.92%
West Pharmaceutical Services (WST)	April 1985	11.5%
Amgen (AMGN)	April 1985	11.44%
Nike (NKE)	April 1985	11.11%
Telefonaktiebolaget LM Ericsson B ADR (ERIC)	April 1985	10.88%
Atmos Energy (ATO)	April 1985	10.84%
US Bancorp (USB)	April 1985	10.8%
Dycom Industries (DY)	April 1985	10.26%
Heico (HEI)	April 1985	9.72%
Fifth Third Bancorp (FITB)	April 1985	9.71%
Modine Manufacturing (MOD)	April 1985	9.46%
Progressive (PGR)	April 1985	9.44%
GlaxoSmithKline PLC ADR (GSK)	April 1985	9.33%
Kimberly-Clark (KMB)	April 1985	9.23%

Large-cap stocks are treated as having a market cap of $10B+.