I'm in the planning stages of a 90 Crew cab short box with a TBI 454 and currently a TH400. I want to put in a 4-speed and 1/2 axles (maybe 3/4, not sure yet) but heard that the chips are different. I found a chip on Summit's site that says for a TBI 454 with a manual trans. Anybody ever use this, or is it just a waste of money?? Has anybody done a swap like this??
Summit chip http://store.summitracing.com/partdetail.asp?autofilter=1&part=JET%2D29010S&N=700+0&autoview=sku
Summit chip http://store.summitracing.com/partdetail.asp?autofilter=1&part=JET%2D29010S&N=700+0&autoview=sku

