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My info is all mixed up. By Dave Shoe - 01/12/2002 1:09:08 AM; IP 216.243.158.216 I can't tell what cam's were used in 1966-67. I do believe the 390GT cam was used from 1967-70, but I see indications that it may have seen some duty in 1966, too. It's possible only the toploader 4-speed PI cars got the solids in 1966, as these were all geared at either 3.25:1 or 3.50:1. 1966 was the last year for 4-speed PI cars. The 1966 C6 428PIs got 3.00:1 or 3.25:1 rears. A couple indications disagree on whether the '66 428PI got the same cam as the '65 390PI, and I can't tell whether this is the .440 lift/282 degree cam or the .499(.500) lift/306 degree cam. I suspect the latter cam was used in the '66 428PI, in part because octane ratings were improving yearly back then, valve spring steels were lasting longer, and the 428PI had higher compression than the 390PI due entirely to the smaller chamber in the all-new full-emissions heads of 1966. Here's my guess, based on info provided: Because of competition from the new Chrysler 440 police cars, and because small-runner "emissions" heads were being used, all 428PI cars got the high lift .499/306 cam at the start of 1966. After a couple months, the C6 428PIs may have been approved to use the 390GT cam, but the slow-selling toploader cars kept the solids. By 1967, the toploader was no longer offered, only 2.80:1 rears were offered in 1967, and all 428PI cars got the 390GT cam from then on. Note also the 345 horse 428 was also offered in police cars in 1967 only, but it was a step below the Interceptor and may have gone into Police Cruisers, not persuit cars. Due to lower compression and older valve spring technology, the 1963-65 390PI cars got the .440/288 cam. Note also that all 428PI engines lost their aluminum intakes just a couple months after the 428CJ iron intake became available midyear 1968. The last couple years of 428PI engines all had iron intakes. Note also that in 1970, the 429 engine was offered in 10.5:1 2-barrel police trim, but it was a runner up to the top line 428PI. I'd like to jump in and talk "A" and "C" blocks for a bit, but I can't right now. Shoe.

This thread, so far...

Skip Navigation Links.  C6ME-A with a A in back of block is it a 390 or 42 -- nick, 01/09/2002  RE: C6ME-A with a A in back of block is it a 390 or 42 -- Greg, 01/09/2002  RE: C6ME-A with a A in back of block is it a 390 or 42 -- nick, 01/09/2002  RE: C6ME-A with a A in back of block is it a 390 or 42 -- Greg, 01/09/2002  RE: '66 PI 428 is solid lifter block -- Mike McQuesten, 01/10/2002  '66 428 PI cam specs -- mikeb, 01/10/2002  Old cop I know says the 428 PI was the -- mikeb, 01/10/2002  RE: '66 428 PI cam specs -- Mike McQuesten, 01/10/2002  Looks like a job for Shoe/perman! n/m -- mikeb, 01/11/2002 My info is all mixed up. -- Dave Shoe, 01/12/2002  RE: My info is all mixed up. -- Mike McQuesten, 01/12/2002  My info (for what it’s worth) -- Barry B, 01/12/2002  '66 pi -- Bob, 01/10/2002  RE: '66 pi -- Mike McQuesten, 01/11/2002  RE: '66 pi -- Bob, 01/11/2002

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