I bought two sets of Lund inserts a year ago, one set is solid, the other perforated. In the fall the four perforated inserts are fitted, as the temp goes down, replace the two lower ones for the solid inserts. Could run with the four perforated inserts all summber but need to keep a close watch on the water temp gauge if towing. Cost of both sets was abaout $C140. Main thing to keep an eye on is the water temp if towing, be prepared to remove the lower solid inserts. Bought mine from Lordo Automotive Parts, took three days for delivery.
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Ian.
'93 D250 ext. cab. Upgraded injectors, 3. 5" exhaust, K & N filter, Xmsn oil cooler and fan, 4 gauge mount, mirror tubes reversed, RACOR fuel filter, larger transmission oil pan.