Hello, I got a problem I hope i could get some advise on,
First of all let me tell what were working with ,
70 chevelle
bbc, 396 60 over
820 oval port heads gasket mathed, comp cam ,valve springs, lifters,
11-250-3 grind 574 intake 578 exhaust lift
284 intake duration at 0.006 tapplet lift
296 exhaust duration at 0.006 tapplet lift
110 lobe separation

seal power pistons forged 2242f60
11.1 comp
4000 stall 350 trans 411 gear with spool
msd egition
750 with proform carb 72 jets front 84 back

now the problem I'm having is , ran the car last week, car ran 14.50 but would not pull in high gear didn't want to go over 4200 rpm only pick up 13 mph from the eighth to the end of the 1/4
it acks like trying to pull a wieght sled!!!!! fuel pressure is at 7.50 lbs
timing at 36 degrees
it continusly slowed to 16.0 seconds any help would be apprecated thanks jethro

Can you or did you monitor fuel pressure as you're running down the track? What distributor? Some HEI's with original modules give out around 4500. Have you tried smaller jets in the rear? any noticeable smoke as you go down track?

hi and thanks for the reply rapid, yea fuel press steady at 7.50lbs, has an hei but the module was removed because i run msd 6al box. the two things that i need to check tommow and not sure its the problem is , my balancer I don't know if it had turned on the rubber and i set timing too far advanced, and oil pressure, it dropped to about 10 lbs as it crossed the 330 ft , I not sure i"m sucking the pan dry. and collasping the lifters or not I herd no nioses or anything like that, car still runs and has 65 lbs pound pressure at idle?????

and also rapid, no noticeable smoke,

Do I understand correctly that you're saying the car initially ran a 14.5 then progressed downward to a 16sec 1/4 mi? If so, the first thing I'd be doing is draining/inspecting the oil and cutting open the filter. Especially with a 10lb reading at the 330'. But thats just me.

What did the mph look like at the end of the 14.5 and 16.0 runs?

http://www.chevelles.com/forums/showthread.php?t=19938

Very good reading on carb tuning. I'm thinking it may be a tad rich, awful lot of secondary jet as I am running 82's square on my 505.

yea i was thinking about the jets being too big in the back, but these were the first runs made and just needed to get a starting point or base line to work from,I will square the carb up also ,have you seen large jets do this ?? I didnt notice any black smoke or plug fouling have you ever herd of sucking the pan dry fellow workers and I were brain storming today at work and came up this possibility,

Hi John, I'm going to do the oil check tommow,hopefully I won't find anything Just to let you know the rest of the story, that i Failed to mention. My son works at a lubercation service center and talks to the amosoil distibuter and convinced my son to use amsoil 0w-30 racing oil, ????? a new senthic type of oil, with a high volume pump and that thin oil do you think sucking the pan dry would cause this problem. Still scratching my head.
thanks for your reply

No way, it has nothing to do with oil at all.
Check to ensure the carb is going WOT, check valve lash. I'm thinking its the tranny.

If it wont RPM, it sounds like the timing is slow. I would find TDC and verify that the balancer is correct. What distributer are you using, and how is it setup? Are you using the vac. advance?, mechanical advance? My 454 (similar build) liked 38 degrees total timing with 16 initial. I used no vac. advance.
The only other thing I can think of that would cause it to be losing power would be a restricted exhaust. (builds to much back pressure) What are you using for pipes and mufflers?

Keep us posted with what you find. Ken

If it was a transmission issue,,,torque converter or clutches,,,wouldnt it still rpm because it was slipping? How would the trans hold the R's down with 4.11's and a spool?

Just throwin out another option, how far apart were the runs? I mean, how much time did the car have to cool down. Wonder if it might be starting to ping more progressively as the engine gets hotter. Have you looked at the plugs to see if there are any signs pointing to any sort of detonation or bad mixture issues? Reguardless of what it is thats holding you back, still check everything cause it might be a combo of more than one thing. That oil pressure worries me as well. Check it all out.