www.the351cforum.com

I’m running a 650 Holley dp on a Weiand Excelerator intake. What jets would you use? Do I need to move to a 750? It’s on a 351c .030, 2v stock heads, Comp Cams DEH 275. 69 Mach1. 4 speed, 4.11 rear.

Thanks

how much RPM do you plan on twisting it?

is this your cam https://www.summitracing.com/parts/cca- ... /overview/

if so, i myself do not see the need to go any bigger than a 750. A 750 might be a little to big really.

Do you have the American open chamber 2v heads or the Aussie 2v heads? are your pistons flat top or dished?
On my .060 flat top Cleveland I have the Aussie 2v heads. I have the same intake as yours. Mine has flat top pistons so with those and the Aussie heads my compression is in the neighbourhood of 10.25. Mine ran so good with the Barry Grant 650 Speed Demon (before Holley bought them) My car is a 70 Cougar with a c4 trans and at that time had a 2500 stall and 4.11 gears and lift bars/traction bars. The best 1/4 mile time was 13.16 with an old Wolverine hydro cam 290/290 duration with .505/.505 lift. Later I knew i was going to a bigger engine so I bought a 750 Mighty Demon and put it on. It didnt go any quicker with that 750 and cam and ran much richer. So I put a bigger cam in it (see link below). That cam woke things up along with a MSD 6Al box. Ran a 12.75@106. (same intake by the way). With the bigger cam I was shifting at 6400.

this is the 13.16 run. small cam with 650 Sorry my mom was videoing for the first time.
https://youtu.be/-9IH5WDPYYM

The bigger cam I have in the 362C https://www.summitracing.com/parts/cca-cl32-238-4
The 12.75 run https://youtu.be/1pcKcbt1Ce4

Im sure some people on here might have had better or worse results than what I wrote you but those are just my real world experiences. Only dyno time the 362 had was with the Aussie heads and Wolverine cam. The best it did in 100 degree shop heat was it's last pull. Layed down 250hp at 6000rpm and 320 at 2800rpm at the wheels. Only carb changes I had to do was up the rear jets 2 sizes. After that it was 12.8 air fuel ratio from 2000 - 6000 rpm sweep. It loved 42 degrees total timing. Distributor was one I pulled out of a 78 ford f100 with a 400 in it. Had a new "Blue" box I bought from O'Reilly auto parts. That MSD 6AL really helped.

P.S. I had the American 2v heads on first with the Wolverine cam and the Weiand intake. Best 1/8 mile times were in the 8.90 - 9.0 range. The Aussie 2v heads helped alot. 1/8 mile time dropped to consistent 8.6. then with the bigger cam and 750 the best 1/8 time was a 8.14@84mph You know for a low stall and not so powerful engine, that thing sure launched hard.

8.14 video https://youtu.be/t077uodMOrY?t=2m39s

Stock Holley jetting unless testing proves different. If you want to have a little insurance, go up 2 sizes in the rear. Otherwise a 650DP is an all around good carb. I have a couple, run them both on a 300 HP 302 and right over to a 560 HP 393C, no changes in jetting.

_________________
Chris - Merkel, TX
http://raceabilene.com/kelly/hotrod
"Owner built, owner abused."

Gday,
Have used an old 4777-1 650 dp in the past, great carb, simar set up, stock jetting i think, head is telling me 67/76?
Did slightly lean out the ifr with the old bent piece of wire strand as per that old dave emanual holley carb book?
Cheers
Paul

Thanks guys for the feedback. Ya can’t beat experience. I’d heard it was necessary to jet up with the Weiand. Just wondered what some of you did with that intake. Appreciate all the replys.