1975 GMC C25 Engine: 5.7L V8; Water Pump to Block; Composite;. 1976 GMC C25 Engine: 5.7L V8; Water Pump to Block; Composite;. 1977 GMC C25 Engine: 5.0L V8; Water Pump to Block; Composite;. 1978 GMC C25 Engine: 5.0L V8; Water Pump to Block; Composite;.
